Still throwing Codes!

[black mamba1]

My OBD II light comes on every third start up or so. I clear them w/ my code reader...2 starts later, its back. I have the O2 sims, still getting codes. Tator wrapped my Belangers w/ so much insulation we cannot fit anymore in there to protect the O2 heaters...still throwing codes.

There is noticeable power loss when the code is thrown, but the power comes right back when I clear the code. But now I am driving around w/ this code reader in my car and I have to hook this thing up and clear this dadgum code every few starts...this is a real PITA!

Any suggestions?

 

[Joseph Dell]

And the code is telling you.... ???

 

[black mamba1]

And the code is telling you.... ???

That would help right?

There are two codes. One says O2 heater. Unfortunately I cannot remember the other, I am going to check it now.

 

[black mamba1]

ok, today it was 3 codes.

PO 172: bank 1 too rich
PO 175: bank 2 too rich
PO 307: Cylinder 7 misfire

Now, I simply went out in the garage and plugged the reader in, my car was cold and had not run since Saturday. Does that make a difference? I know we might be a tad rich due to the mods...but misfire?

 

[fqberful]

ok, today it was 3 codes.

PO 172: bank 1 too rich
PO 175: bank 2 too rich
PO 307: Cylinder 7 misfire

Now, I simply went out in the garage and plugged the reader in, my car was cold and had not run since Saturday. Does that make a difference? I know we might be a tad rich due to the mods...but misfire?

It sounds like the O2 sensors are too far from the head. Does this car have headers? Vipers for some reason seem to have this problem with headers. I have long tube headers in my SRT10 Truck and they are way back in the collectors and never experienced this, but have heard of it in Vipers. When discussing this with M&M for my Viper headers they indicated they'd seen a load of it too and placed the O2 sensor way up near the head in one pipe. Even the stock exhaust has the sensors pretty close to the head.

As for the cyl 7 misfire, that can come from a very rough idle, fouled plugs, big cams, or even a real misfire like a coil pack, wire or plug, or fuel injector, bad valve, bad crank sensor, etc.

As for the 3rd trip and MIL light, that's the way O2 sensor MIL's work in many cases, the PCM has to have 3 "trips" with a failure to turn it on. A trip is usually defined as up to temp and above a certain speed for some distance. The reason you lose power is because when an [ primary upstream ] O2 MIL trips it places the PCM into "limp home" mode and it runs strictly off the fuel/timing maps which of course aren't optimum, but they are good enough to get home. The running rich could be a function of poor O2 sensor placement or failing O2 sensors or something in the fuel like lead or other fuel additives messing with them.

Good luck!

 

[Joseph Dell]

It may also be that your vec3 isn't tuned well and it is really running too rich at a point in time. I'd data-log that if you can to get an idea...

 

[pteam]

If you got this many problems, you might want to bite the bullet and take it to the dealer, before something really goes wrong.

 

[black mamba1]

I do have an aftermarket cam and headers. I have been getting the codes every since the Belangers went in, for over a year now. Its just now that I am actually clearing them myself.

I put in O2 simuators in to fool the computers that the O2 sensors would send the correct signal to the PCM at all times to not trigger the codes. They are not working and no one seems to know why. My Viper tech tells me this is just something I and many other Vipers w/ similar mods will just have to live w/....clearing the friggin codes every two or three trips.The car does idle deep and rough, like a car w/ ported heads and cams usually do...we insulated those O2 sensors before removing them and putting in the sims. Any idea where guys are repositioning their O2 sensors w/ Belanger headers?

 

[black mamba1]

If you got this many problems, you might want to bite the bullet and take it to the dealer, before something really goes wrong.

The dealer would throw me out of his shop once he sees all my mods!

 

[fqberful]

I do have an aftermarket cam and headers. I have been getting the codes every since the Belangers went in, for over a year now. Its just now that I am actually clearing them myself.

I put in O2 simuators in to fool the computers that the O2 sensors would send the correct signal to the PCM at all times to not trigger the codes. They are not working and no one seems to know why. My Viper tech tells me this is just something I and many other Vipers w/ similar mods will just have to live w/....clearing the friggin codes every two or three trips.The car does idle deep and rough, like a car w/ ported heads and cams usually do...we insulated those O2 sensors before removing them and putting in the sims. Any idea where guys are repositioning their O2 sensors w/ Belanger headers?

The O2 SIMMS go on the downstream O2 sensors only and would not throw those codes. Unless you wired them to the upstream ones ? The purpose of the SIMMS is to fool the PCM into thinking the cats are okay so you can remove them.

If you're going to relocate the upstream O2 sensors they would probably go in the cylinder #5 and cylinder #6 pipes about 4" - 6" from the head.

The upstream O2 sensors allow the PCM to control the mixture from 0% to about 75% throttle, after that it runs on the maps. The downstream O2 sensors allow the PCM to monitor the cats.

If you've got a VEC in the mix, then you may have issues there as well since it's function in life is to lie to the PCM and make it behave differently based on modified inputs, the O2 sensors being one of those.

 

[black mamba1]

Ok, so the downstream simms are no longer the suspect. Its the upstream ones are they responsible for the bank1 and bank2 reporting as too rich?

 

[Tusc]

Forgive an ignorant question. I know everyone uses the Vec1/2/3 for their cars to modify signals to the PCM and that seems to work in most cases. What is the prohibitive factor keeping owners from installing a quality aftermarket DFI system and being rid of the problems I read about?

 

[RobZilla]

I too am running into this problem. Are you letting the engine warm up properly before driving. The O2 sensor has an electronic warming device to heat them until the exhaust warms up to take over this operation. I get an error on bank 2 and I suspect this is the malfunction.

I spoke with the Viper Wizard who advised I insulate them. Yours are already insulated, so thats not the problem. You could be looking at a problem with the placement being too far downstream in the collector. Also I've heard that the sensor works on a very low voltage so the connection to the PCM needs to be soldered. Finally your Vec could be interfering as said in the above responses.

I've been clearing the code every couple of weeks until I have the time to really take a look into this error. If all else fails Ill have to replace the bank 2 sensor and cross my fingers.

P.I.T.A. for sure but sometimes that the price with all these mods.

 

[KEast]

Why not tune the factory PCM and get rid pf the VEC-3? You are not running that wild an engine.

I am using a factory comp with a tune from DC Performance on a 522 N/A motor and its runs great

The issue you have with the misfire is most likely the cam you have. Rough idle = Misfire trip..

 

[ViperTony]

I do have an aftermarket cam and headers. I have been getting the codes every since the Belangers went in, for over a year now. Its just now that I am actually clearing them myself.

I put in O2 simuators in to fool the computers that the O2 sensors would send the correct signal to the PCM at all times to not trigger the codes. They are not working and no one seems to know why. My Viper tech tells me this is just something I and many other Vipers w/ similar mods will just have to live w/....clearing the friggin codes every two or three trips.The car does idle deep and rough, like a car w/ ported heads and cams usually do...we insulated those O2 sensors before removing them and putting in the sims. Any idea where guys are repositioning their O2 sensors w/ Belanger headers?

Keith, I know that the Belanger SRT headers are a bit different than GenII but hopefully this will apply here...O2 heater codes can be thrown after installing belanger headers on GenII because the upstream O2 sensor can be located further back from the OEM header location. In this location, they take longer to heat up. The O2's don't heat up fast enough and O2 heater codes get thrown. The GenII Belanger headers now have two O2 mounting locations: In the primaries and further back in the collector. I chose to mount them in the collector to catch each bank as opposed to reading one cylinder per bank. Not sure about the GenIII style. I followed Chuck's advice and insulatd the O2's but no luck. After about 3-5 trips I get the heater codes thrown and the car runs pig rich. I ended up buying quick fire O2 sensors from DC Performance and the problem was solved. Again, this was for a GenII but hopefully helps here. - tony

 

[black mamba1]

Ok, does DC Performance sell quick fire O2 sensors for Gen 3's?

 

[black mamba1]

Why not tune the factory PCM and get rid pf the VEC-3? You are not running that wild an engine.

I am using a factory comp with a tune from DC Performance on a 522 N/A motor and its runs great

The issue you have with the misfire is most likely the cam you have. Rough idle = Misfire trip..

This idea sounds interesting. How do u tune the factory PCM? I know the Vec piggybacks the factory PCM, that is the only method I am aware....my question here is probably the dumbest in here yet!
I know that DC offers a reflash....what exactly is this "reflash" and is that related to factory PCM tuning?

 

[black mamba1]

Keith, I know that the Belanger SRT headers are a bit different than GenII but hopefully this will apply here...O2 heater codes can be thrown after installing belanger headers on GenII because the upstream O2 sensor can be located further back from the OEM header location. In this location, they take longer to heat up. The O2's don't heat up fast enough and O2 heater codes get thrown. The GenII Belanger headers now have two O2 mounting locations: In the primaries and further back in the collector. I chose to mount them in the collector to catch each bank as opposed to reading one cylinder per bank. Not sure about the GenIII style. I followed Chuck's advice and insulatd the O2's but no luck. After about 3-5 trips I get the heater codes thrown and the car runs pig rich. I ended up buying quick fire O2 sensors from DC Performance and the problem was solved. Again, this was for a GenII but hopefully helps here. - tony

Yeah, when the code comes on I get backfire in my exhaust (running rich) which I dont normally get. Nor do I get the power surge at 4000 rpm what I get when the code is not there.
I think I will DC Perf. a call. Someone asked if I let my car warm up enough before driving off....I must admit I do not. My car is LOUD and a couple of my neighbors might get pissed if I idle her in the driveway for over 3-4 minutes early in the morning or after 9 or 10 pm at night.

Also, many Viper owners think throwing codes does not really affect power...that is a load of crap! Those codes that revert the Viper back to factory limp mode settings rob gobs of power!

 

[Viper Specialty]

hmm.... running rich and misfire? sounds to me like you may have catalytic converter damage. Plugged cats will cause high backpressure and misfires. Random Misfires will cause the computer to richen the mixture. Partially plugged converters will richen and richen the mixture until they pop rich codes, along the way setting off the misfire monitor. Once the misfire is detected, the adaptives reset temporarily (and lock to Zero) until code is cleared. When a missfire code is set, the car is not put into Limp, it is Zero'd out. It SHOULD feel perfectly normal if the tune is correct. Your lost power is likely the excessive back-pressure.

My guess is that the place that tuned it attempted to tune out the WOT Fuel Delay Timer inherent with SRT PCM's, which dumped fuel into the converters on the dyno during every pull, and every time you mash the gas. (Cat Killer) It can only be removed at the PCM level (or signal clamping, but still not as good as deleting it), in-line fix attempts can only mask it temporarily- but the PCM will always win.

 

[Viper Specialty]

This idea sounds interesting. How do u tune the factory PCM? I know the Vec piggybacks the factory PCM, that is the only method I am aware....my question here is probably the dumbest in here yet!
I know that DC offers a reflash....what exactly is this "reflash" and is that related to factory PCM tuning?

The SCT-Flash software that we have is what needs to be used in order to flash-tune the PCM. Everything can be changed with this software, down to the base fuel tables.

Yes, the VEC as a whole can go away on an N/A Car. Yes, Re-flash is a kin to PCM tuning. However, there is a BIG difference between a "box-tune" and an actual fuel map re-write for your car. A custom re-write is absolutely not possible without your car in hand, unless someone already did one on an identical setup. This would never happen unless it was a tuner built cookie-cutter car, which it is not.

I could swear that I have talked with you about this before.....?

 

[black mamba1]

The SCT-Flash software that we have is what needs to be used in order to flash-tune the PCM. Everything can be changed with this software, down to the base fuel tables.

Yes, the VEC as a whole can go away on an N/A Car. Yes, Re-flash is a kin to PCM tuning. However, there is a BIG difference between a "box-tune" and an actual fuel map re-write for your car. A custom re-write is absolutely not possible without your car in hand, unless someone already did one on an identical setup. This would never happen unless it was a tuner built cookie-cutter car, which it is not.

I could swear that I have talked with you about this before.....?

You have, but I am embarassed to say that when we first discussed this I did not understand or appreciate your information in full..it was somewhat over my head at the time...but now it all makes so much sense. I am really lucky to have you this close to where I live!

 

[black mamba1]

hmm.... running rich and misfire? sounds to me like you may have catalytic converter damage. Plugged cats will cause high backpressure and misfires. Random Misfires will cause the computer to richen the mixture. Partially plugged converters will richen and richen the mixture until they pop rich codes, along the way setting off the misfire monitor. Once the misfire is detected, the adaptives reset temporarily (and lock to Zero) until code is cleared. When a missfire code is set, the car is not put into Limp, it is Zero'd out. It SHOULD feel perfectly normal if the tune is correct. Your lost power is likely the excessive back-pressure.

My guess is that the place that tuned it attempted to tune out the WOT Fuel Delay Timer inherent with SRT PCM's, which dumped fuel into the converters on the dyno during every pull, and every time you mash the gas. (Cat Killer) It can only be removed at the PCM level, in-line fix attempts can only mask it temporarily- but the PCM will always win.

During my first dyno run a couple months back we got so rich on one run the room filled w/ white smoke and we all had to vacate the dyno area for about 10 minutes. If I have Cat damage:

1. How can I tell exactly?
2. What is the remedy (I guess new cats right?)

 

[Viper Specialty]

During my first dyno run a couple months back we got so rich on one run the room filled w/ white smoke and we all had to vacate the dyno area for about 10 minutes. If I have Cat damage:

1. How can I tell exactly?
2. What is the remedy (I guess new cats right?)

White smoke= extreme amount of fuel or coolant (you would know coolant for certain just by its sweet smell)

1. a. Back-pressure test, make sure its within limits. This will indicate a clogged cat, but will likely not detect the early signs of cat damage.
b. Internal Visual exam, look for molten material in the converter substrate, plugged cells (especially in the center cat core)
c. External Visual Exam, look for holes in the cat, hot spots, etc. A plugged, overheated cat can easily build enough heat and pressure to pop holes in the canister.
d. The exhaust note will likely sound funny at times.

2. No repair is possible, only replacement. However, you need to find the problem first before replacement, or it will happen again quickly.

Just remember during an exam that the converter cells are a few inches long. The surface usually tells you nothing-you need a bright light and look THROUGH the cat.

 

[fqberful]

Ok, so the downstream simms are no longer the suspect. Its the upstream ones are they responsible for the bank1 and bank2 reporting as too rich?

Correct, the FSM says that these codes are derived from an abnormal high lean correction. This is specific to the upstream O2 sensors.

Also, if you're N/A get a B&G or DCP flash on your PCM and get rid of the VEC. Dave @ B&G does a good job and his flashes for N/A cars work quite well. He can also set you up with an SCT loader and do custom tunes for you based on dyno pulls and A/F maps. I think DCP offers the same services.

 

[Sean Roe]

PO 172: bank 1 too rich
PO 175: bank 2 too rich
PO 307: Cylinder 7 misfire

Hi Everyone,
I've read through this thread and feel I need to add some information to clarify and correct some people's thinking.

To preface, this is not a problem caused by headers, one that is related to O2 simulators, one that cannot be corrected with a slight tune change or one that requires changing over to a different engine management strategy and starting over from square one. This is easy.

At cruise and idle conditions after warm up, the factory PCM goes into an adaptive mode called closed loop. In this mode, the PCM looks at the upstream oxygen sensor voltage and adjusts the pulse width of the injector accordingly. Lean (low O2 voltage) makes it increase the pulse and rich (higher voltage, and we're only dealing with 0 to 1V here) makes it decrease the pulse. There is a range of adaptive ability within the PCM. The PCM keeps making these adjustments, watching the O2 voltage and changing the injector pulse adaptive. If a condition arises where the PCM reaches the end of its adaptive range, but the target O2 voltage is not reached, the check engine light will come on.

You have codes for both banks reaching the end of their adaptive. When you modify an engine, you change the vacuum level the engine idles at. When the vacuum is lower (closer to 0), the PCM interprets the vacuum as load (as though the AC is on) and moves to a richer fuel table. If in closed loop, it then has to use its adaptive to reduce injector pulse and get back to the correct O2 voltage. When you clear the code, you are not clearing the embedded adaptive value in the PCM and the light will come right back on when the adaptive value is seen as reaching the end again. Disconnecting the battery or all three plugs on the PCM CLEARS the adaptive and resets it to zero. Does this correct the issue that caused it, no, but it will keep the light off for a longer period of time.

The correct fix for this is to go over to Chucks and have him hook up his scan tool so he can monitor the adaptives. He can adjust the fuel load value of the VEC at that vacuum level and pull out the perhaps 0.3 milliseconds of fuel that is needed to get the adaptive back in the normal range. Don’t even consider the cause of the misfire code until the fuel of the engine is tuned correctly so this code does not occur.

Furthermore, Dan, you are incorrect about a piggyback / in series device not being able to dial out the initial lean WOT closed loop condition. We run the upstream O2 wires through the VEC3 and feed the PCM a stoichiometric voltage as soon as the engine load goes up to about 3 inches of vacuum. The result is the PCM does not alter the injector pulse by way of adaptive during that first second and a half at WOT. We had to overcome that before we could release the Supercharger kit made for the trucks. However, other blower kit makers have not done anything about it.

For the owner of the 2000 with headers getting the code in Jacksonville, you may get relief from changing the upstream sensor(s) over to ones that heat up faster. Headers on a 2000 car can cause that problem when the sensor is too far downstream and doesn’t heat fast enough. The other fix is to move the sensor up closer, in a single primary tube.

Regards,
Sean

 

[Viper Specialty]

When you clear the code, you are not clearing the embedded adaptive value in the PCM and the light will come right back on when the adaptive value is seen as reaching the end again. Disconnecting the battery or all three plugs on the PCM CLEARS the adaptive and resets it to zero. Does this correct the issue that caused it, no, but it will keep the light off for a longer period of time.

While it will certainly come back if it isnt corrected, a PCM Misfire DTC will reset all adaptives to Zero, as the PCM knows the AFR cannot be "trusted" during a misfire condition.

The correct fix for this is to go over to Chucks and have him hook up his scan tool so he can monitor the adaptives. He can adjust the fuel load value of the VEC at that vacuum level and pull out the perhaps 0.3 milliseconds of fuel that is needed to get the adaptive back in the normal range. Don’t even consider the cause of the misfire code until the fuel of the engine is tuned correctly so this code does not occur.

Considering the information about lost power in this case, extremely rich run on the dyno, and the accompanying codes, I would certainly not rule out the cats yet on this one. It is also highly probable there is more than one thing happening here.

Furthermore, Dan, you are incorrect about a piggyback / in series device not being able to dial out the initial lean WOT closed loop condition. We run the upstream O2 wires through the VEC3 and feed the PCM a stoichiometric voltage as soon as the engine load goes up to about 3 inches of vacuum. The result is the PCM does not alter the injector pulse by way of adaptive during that first second and a half at WOT. We had to overcome that before we could release the Supercharger kit made for the trucks. However, other blower kit makers have not done anything about it.

What you are refering to is a signal clamp, not really "dialing it out", and also assuming the O2 sensor clamps are even connected in this case. On that note, clamping that signal only prevents the PCM from removing fuel, but it still will not allow the PCM to increase the pulsewidth in line with the WOT/PT fuel multipliers until the timer expires, in effect only curing half of the problem. If the customer has a VEC-2 or a VEC-3 without the clamps connected, attempting to dial out the WOT Timer will be a futile effort in any case. Removing it at the source is a better approch now that it is available, and would be part of the overall tuning correction for this car in a best-case scenario anyway.

 

[RobZilla]

Sean, thanks for the extensive write up. Great information. I spoke with Chuck Tator who basically advised me the same thing. Could be the sensor, but he suggested 1. I wrap them 2. check the connection and finally if all that fails 3. move the sensor upstream into one of the headers or buy a new one.

 

[steponz]

I had a bad cat a couple months ago.....

I could tell by putting my hand over the exhaust pipe to see if its coming out normally..
Usually if you have a bad cat it won't come out very well....

Also my cat was clogged so bad that you couldn't tell my looking through the ends...
The cat was cut in half and was totally melted...

This is what happens when your car is running way too rich....

Joe

 

[plumcrazy]

id go back to chucks and let him diagnose it. its way better in person than on the internet. but im with Daniel, im betting a cat from that bad tune ya had for a while. and you did put a couple few miles on it with the bad tune....

 

[black mamba1]

Sean, thanks for the info!
Now, for us laymen...basically:

My car is running at conditions outside of the adaptive values of the PCM. These adaptive values need to be changed to accomodate my mods. I think you are saying my adaptive values either have not been changed or have been changed to a value that is still not in the range of where the car wants to operate at. So if the PCM has me running rich it will reduce the injector pulse to try to get the proper voltage (and lean things out), but if it has reduced the injector pulse as much as it can and the correct voltage is still not seen, it will not reduce the pulse anymore..it will simply throw the code, having bottomed out on injector pulse reduction.

I think you are also saying that just b/c I clear the code it does not mean I have brought the injector pulse back to the correct operating range b/c I have not zeroed it out...meaning it remembers my lean condition and will stay there. But does this condition put the car in limp mode? Does the car go into limp mode here or simply the leanest/lowest injector pulse setting w/in its range?

Does the car go into limp mode when the light comes on? Or does it remember the last limp mode setting and stay there w/ no light until the 3rd start or so and until we disconnect the battery?