Anyone Replace Stock Cats with High Flow Cats?

xRUSTYx

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Hey Guys ...

Love my almost 2 week old Viper :) Had a couple exhaust questions ...

Anyone running stock manifolds & exhaust and have simply replaced the (4) cats with (2) high flow cats (Like Roe - http://www.roeracing.com/productcar...nverter-Set-2003-2009-Dodge-Viper-215p435.htm)

My goal is to rid the cabin of excess heat, while boosting sound by just a tad.

If anyone run's this setup, would love to hear it. Through my search, I found many running High flow cats + aftermarket exhaust, but none so far of just running the high flow cats with stock everything else :)

Thanks guys!
Rusty
 

TowDawg

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Just lose the cats completely. I know a lot of people run the high-flows, but there also seem to be quite a few that issues with them clogging, burning side sills, etc.

Also, look getting an exhaust system (you can skip headers for now if you want) if you want to lower the cabin temps. The Gen III stock exhaust crosses over (your drivers side exhaust pipe is actually from your passenger side header and vice-versa) behind your seat and that is where a lot of the cabin heat comes from. All of the aftermarket kits get rid of that crossover. You can probably find a used stock Gen IV exhaust system out there for pretty cheap and install that is money and loudness are a concern. They got rid of the crossover on the Gen IV's.
 
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AbsolutHank

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You really need to get rid of the crossover first, and then deal with the cats. Like already mentioned, for what you are after, I'd hunt down a used 08 muffler/tip combo, and maybe even just remove the secondary cats if you wanna save a little cash instead of going for the H/F cats
 

eucharistos

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Q:

........My goal is to rid the cabin of excess heat, while boosting sound by just a tad.......

A:

You really need to get rid of the crossover first, and then deal with the cats. Like already mentioned, for what you are after, I'd hunt down a used 08 muffler/tip combo, and maybe even just remove the secondary cats if you wanna save a little cash instead of going for the H/F cats

completely catless is loud :omg: (but fun :D )

congrats on your new viper :2tu:
 
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xRUSTYx

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Thanks for the responses guys!

Do any companies make a product that can get rid of the crossover? while keeping the rest of the exhaust in tact?
 

Flexx91

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Thanks for the responses guys!

Do any companies make a product that can get rid of the crossover? while keeping the rest of the exhaust in tact?

There is no way to simply get rid of the crossover without changing out the entire system downstream of the mufflers. There are multiple pieces that starts at the muffler connection and what you see sticking out of the sill is not a short exhaust "tip" that can be removed. The least expensive way is to install a pair of used takeoff Gen. IV mufflers/tips (as was previously mentioned). That part is relatively simple once the side sills are removed but you still have to remove the crossover which requires you to remove the belly pan and heat shield. If you're going to go through all of that, you may as well get rid of the entire system, spend a few extra bucks, and install a Corsa system.
 

Viktimize

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Thanks for the responses guys!

Do any companies make a product that can get rid of the crossover? while keeping the rest of the exhaust in tact?

Yes, Dodge makes one for all Vipers manufactured as an 08 model year and up. Just get your hands on one of those set ups from someone who upgraded to Corsa....................As it's been mentioned.
 
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xRUSTYx

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Ah ha ... Gotcha.

Thanks for clearing that up guys. Figured the crossover was before the mufflers (before/after cats), not after :)

This picture really helped!

You must be registered for see images
 

Flexx91

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Yes, it can be a little confusing if you have never seen a fully assembled Gen. III stock exhaust setup. Also, you can visit Corsa's website for the installation instructions (download the .pdf) on their system. It contains all of the necessary steps and suggestions for the Gen. III stock exhaust removal. The two most time consuming (but not difficult) steps are removing the sills (getting to that dreaded foward sill nut) and "wiggling" out the crossover from the frame.
 

cubican

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Get your self a set of Corsa cat back that will take care of you with out any Drone. If you needed louder then go for the HF cats or gutt the second cat. If you run no cats is going to be loud as hell plus on the vert the fumes will drive you nuts.
 

Vip1

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I replaced mine with Random Teck Hi Flow was told there would be no issue with getting the car to pass inspection,my car has failed twice, check engine light comes on and off. Contacted Random Teck was told I have 3 year warranty if I want to send them back for refund I like the sound and didn't put them on just remove them or spend 1100.00 for new computer.
 

Chrissss

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Hey Guys ...

Love my almost 2 week old Viper :) Had a couple exhaust questions ...

Anyone running stock manifolds & exhaust and have simply replaced the (4) cats with (2) high flow cats (Like Roe - http://www.roeracing.com/productcar...nverter-Set-2003-2009-Dodge-Viper-215p435.htm)

My goal is to rid the cabin of excess heat, while boosting sound by just a tad.

If anyone run's this setup, would love to hear it. Through my search, I found many running High flow cats + aftermarket exhaust, but none so far of just running the high flow cats with stock everything else :)

Thanks guys!
Rusty

Replaced mine with Roe high flows. Love em. Completely took care of the cabin heat problem. I strongly do not recommend removing all cats completely.
 

PirateViper

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I replaced my cross over with an 08 exhaust and Roe HF cats.Greatly reduced heat and sounds great!
 

Viktimize

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I had a quick question and figured I would just revive this thread instead of making a new one.

My Roe HFC's and Corsa are getting installed today. Has anybody had any issues with check engine lights after doing an install like this?? Last thing I want is to have to go back in and install sims after the install is complete.

I do have a SCT tuner on the car already. Does that tuner automatically kill the second O2 sensor anyway??
 

VIPER GTSR 91

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I replaced mine with Random Teck Hi Flow was told there would be no issue with getting the car to pass inspection,my car has failed twice, check engine light comes on and off. Contacted Random Teck was told I have 3 year warranty if I want to send them back for refund I like the sound and didn't put them on just remove them or spend 1100.00 for new computer.
THIS is exactly why I dont want to have Hi Flow cats installed on my Gen 4. New puter would work but then the hassle of putting the OEM back on to pass TX inspection.
 

TowDawg

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I had a quick question and figured I would just revive this thread instead of making a new one.

My Roe HFC's and Corsa are getting installed today. Has anybody had any issues with check engine lights after doing an install like this?? Last thing I want is to have to go back in and install sims after the install is complete.

I do have a SCT tuner on the car already. Does that tuner automatically kill the second O2 sensor anyway??

Only if the tune was written to "trick" the system. Who did you buy your tuner/tune from?
If they didn't automatically put that in the tune that you have now, they can just add it and email it to you.
 

Viktimize

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I bought the tuner off a member here Darbnik. I got the cats from him as well. And now none of this stuff matters. Cats are too long for some reason, and the actual cat part of the pipe is in the sill for some reason? So you can't even cut the pipe to fit with my Corsa because you would have to cut right into the cat. And the cat has no hangers for some reason either. They are supposed to be Roe Hi flos, but they must be like the first set to ever roll out of the company before they figured out they were crap and re-engineered a new set.

So now my installer is just going to cut the whole thing off and weld in some straight pipe. I'll get the O2's tie wrapped to the frame and see what happens.
 

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