Took the cats out. Definitely louder.

[Rizzo]

Well, I was contemplating taking the cats out and decided to try it. What should have been a relatively easy job turned into a long affair. The car already has the Borla cat back on it but while we were putting things back together we noticed that one of the rear exhaust hangers was missing a bolt. It was snapped off in the hole with only a few threads showing. Only way to access it was to take the hanger off which meant removing the other bolt. Guess what. Seized in solid. Only way to get it off was snap it and start drilling. Ended up taking a looooong time to finally get it drilled out, re tapped and installed properly. Changed all the fluids and started it up. WOW !!. Nice sound. Not too loud at idle but certainly louder when you give it a little gas. It has a deeper rumble to it and you can really hear the lope to the cam now. It is definitely louder in the car when you are going through the gears and would be too loud for cruising long distances.....until you hit 6th gear. It drops the rpm's to a perfect level and is just as quiet as before in the cab. Best part was that it didnt throw any codes. I heard that some 98's would throw codes and some wouldnt. I got lucky....so far...lol

 

[FE 065]

2 or 4 muffler Borla catack?

 

[Rizzo]

Its the 2 muffler system.

 

[FrViper]

Also provide improved horsepower. On Gen.1 or 2 about 25HP.

 

[FE 065]

I'm still pondering a move to 3"OD catback pipe.. My last iteration under the sidesills, already devoid of cats and resonators, was quieter and showed 0 psi backpressure at WOT throughout the RPM range with OE 2.25" post resonator pipes.

- Just what I hoped it would do actually..

 

[Darth Menace]

judging by this thread bein 4 years old I know im not robbing it, so i though id post here instead of start a new one. By saying on Gen 1 or 3 about 25hp. You get that much just removing the cats? does the thing reek like gas (just going by what my mustang smelled like with punched cats) any cons to doing this?

 

[plumcrazy]

i seriously doubt any hp gains. it does smell though. i have had mine off since it got built (aboiut 15K miles ago) i dont mind the exhaust smell, its not that bad but it is there. mine also might be worse as it is SC'd ?

the advantages are ice cold sills, cheap to remove and sounds better by far. and you can always put them back on if you dont like it

 

[Darth Menace]

no HP gains thats a bummer. Was sounding like an amazingly cheap mod for that hp

 

[Fatboy 18]

I notice the comment about the car not throwing up any codes!

Well in my case (a 2000GTS) when I first removed the cats the car did not throw up any codes.....But after around 300 miles or so the engine management system re-sets itsself and now my car is throwing up codes. Saying Catalists not working

I have re-set the code display once (so far) but this weekend the engine light came on again so I will borrow my friends code reader and check if its the same codes? Im not too bothered at the moment as the car will soon be going into storage over the winter months for a couple of mods, one being Belanger Headers

 

[v10enomous]

You need to do the Spark Plug Non-fouler over the rear sensor mod and the light stays out.

 

[Rizzo]

Man this thread is old. I miss my old 98. It was a great car. 15 or 20 hp wont happen with cat removal. Its more like 5 to 7 but the car was way cooler on the sidesills and it sounded a lot better. I didnt notice any stink but tended to drive it outside rather than in the garage. Haha

 

[banton]

The cat removal may not gain as much power on a nearly stock Viper, but does in cars that have more mods. I lost 23 peak rwhp on my heads/cam GTS when I went from no cats to high-flow cats in order to pass emissions.

 

[Leslie]

I want to remove my cats as well, have high flows now (GenII)...just not sure how to get up into the manifold area. My mechanic had weled the high flows.

 

[ViperTony]

I want to remove my cats as well, have high flows now (GenII)...just not sure how to get up into the manifold area. My mechanic had weled the high flows.

I think yours would be easy. No need to get to the manifold (assuming header area). Remove side sills, cut out cats, weld in straight pipe. Done. I was thinking of doing the same but I may weld in v-bands so come emissions-testing time I can pop the cats back in.

 

[joemcmillen]

ROE has the parts and not too expensive. I purchased 30" spool pieces with new clamps and installed yesterday. Not too difficult. Cut the tubes to size, as the left was 20" and the right was 17". Get the parts, disassemble, measure, cut and install.

 

[Fatboy 18]

I want to remove my cats as well, have high flows now (GenII)...just not sure how to get up into the manifold area. My mechanic had weled the high flows.

My original set up 2000 stock headers and flexi pipe still in place.

You can see the step up to a 3" Cat back Bellanger exhaust system.

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This is how my current set up looks.
Still with stock headers and flexi pipe in place.

I purchased a length of 3" mild steel pipe from local auto store and 2 Clamps. I removed the clamp at the rear of the cat then using a sizal saw cut off the cat from the factory pipe. I first cut a series of slots in each end of the 3" tube, sleeved the new larger 3" pipe over the stock turn out and using some exhaust repair putty and some parts of a cut down beer can to wrap around the stock turnout, then clamped down onto the original pipe to seal things up.

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Factory cat removed

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I now have a set of Bellanger headers sitting in my garage which will be going on in the next couple of months

Have to say the diffrence in heat in the side sills is amazing....Much cooler

 

[GTS Bruce]

V bands are a beautiful thing and the only way to go. Quick and easy change from cats to straight pipes. GTS Bruce