Not Cats? Rear O2 sensors?

[rogerdarabbit]

Has anyone used what is referred to as "mechanical" o2 simulators, when running with a cat delete exhaust system, on their Viper effectively? I am going to get rid of the cats and resonators on my '98 GTS and go with headers and dynomax race bullets...hoping to prevent throwing a code.

Using sparkplug non-foulers to space the sensor out of direct exhaust flow

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This was found over on another forum but is being done with a 4 ******.

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Thanks

 

[cabinetman]

In my experience, on my 97 coupe I did nothing but headers (off a 98) and cat delete, and had no default codes. Personally, I wouldn't use any O2 simulators. What can happen is if there is a code thrown that is not related to the O2 levels the simulators may mask the real problem. Just do the delete and enjoy the extra HP

 

[RobZilla]

Im on the fence with this one. I have the sims and every once in a while the code will throw anyway. It seems to throw if I don't let her warm up all the way, or I start it just to back it out and wash. Usually on the return to the garage the code is tossed. IMO delete the cats and see what yours does. If there is a code, put the sims in.

 

[GTS Bruce]

Syms not needed on your year car. GTS Bruce

 

[plumcrazy]

that setup will work fine

 

[EastTnMan]

You will have to see what yours does..my 97 GTS throws a code after 1000 miles or so, ever since I removed the cats, resonators and muffler. I am running 2 short glasspack mufflers instead. I know many 97's do not, but mine does, and has ever since I changed the exhaust. I simply plug in my OBDII reader and erase the code every time it happens...which is not often, every 1000-1200 miles or do. You will love the cat delete!
Mike

 

[Viperless]

Has anyone used what is referred to as "mechanical" o2 simulators, when running with a cat delete exhaust system, on their Viper effectively? I am going to get rid of the cats and resonators on my '98 GTS and go with headers and dynomax race bullets...hoping to prevent throwing a code.

Using sparkplug non-foulers to space the sensor out of direct exhaust flow

You must be registered for see images attach

This was found over on another forum but is being done with a 4 ******.

You must be registered for see images attach

Thanks

Been using those for over a year on my '99. Never thrown a code.

 

[CROM]

I have a set of Roe Sims sitting around if you are interested.

 

[Sean Roe]

I think that setup is best described as working on some cars and not others.
On a '96, you don't even have to run sims if you take out the cats.
The earlier OBDII cars have the highest chance of it working (97-98).
On the later PCM's (certainly 2000+), it would probably not.
It may seem like it works because the code will set later, but it will still set.
It just takes time for the PCM to determine the fault has happened enough to turn the light on (hard code), even though it may be a pending code for some time (soft code, no light).

 

[Rizzo]

I have a 98 also with no cats and no sims or spacers. I have no codes. Try it first without and if you get a code then put the sims in.

 

[PS78]

On the later PCM's (certainly 2000+), it would probably not.
It may seem like it works because the code will set later, but it will still set.
It just takes time for the PCM to determine the fault has happened enough to turn the light on (hard code), even though it may be a pending code for some time (soft code, no light).

...so i guess be prepared for the light to come on yet: de-catted and before connecting replacement tube & muffler up ran the engine to discover the sound (yum!) - no codes from the detached sensors. connected the new arrangement up (inc. orig. sensors) and went out on test run and still no light/ code.. so far, so good

 

[plumcrazy]

wont for a few miles. like 100 i think. keep driving it but i bet its gonna be fine like mine with 5k miles since using them

 

[Frankster]

My 96 Venom 600 has Borla headers with no cats and the spiral flow Moroso mufflers. After the cat delete a few weeks ago mine has not thrown a code.

Problem is I'm running extremely rich (black soot all over the rear). Anyone know of a cure? Can the PCM be flashed with a new fuel map or something like that?

 

[Mopar Boy]

I think that setup is best described as working on some cars and not others.
On a '96, you don't even have to run sims if you take out the cats.
The earlier OBDII cars have the highest chance of it working (97-98).
On the later PCM's (certainly 2000+), it would probably not.
It may seem like it works because the code will set later, but it will still set.
It just takes time for the PCM to determine the fault has happened enough to turn the light on (hard code), even though it may be a pending code for some time (soft code, no light).

What is recommended for a 2002 then if you do not want codes Also, by running catless, is there a downside to it.

Robert

 

[Boxer12]

I am curious about this too. My fear is an incorrect a/f ratio, and probs with the tune.

 

[99 R/T 10]

Switch out your PCM with a 98 or earlier computer. That will eliminate the need for O2 Simms.

 

[Boxer12]

Switch out your PCM with a 98 or earlier computer. That will eliminate the need for O2 Simms.

Can the PCM be flashed? (and reflashed to OEM, if desired)

 

[vincy]

Where can you get sims for a 2008? How many are needed? Thanks