performance exhaust no cats?

hi any owners with performance exhaust upgraderunning no cats on a 94 -95 vt does your ck eng light come on from the exhaust systems?

I don't know if the 94-95 is like my 99, but on the 99 there are two sets of cats, a pre-cat and a regular cat (my Testarossa is also like this). You can remove the 2nd set of cats with no problem, but changing the pre-cats seems to be an issue.

 

My car has a Larini exhaust with bypass pipes replacing the secondary cats (pre-cats still in place) and all is fine. Have heard of numerous others with the same setup.

the set up im getting will delete all my cats but i beleive on a 94 obd 1 theres no catalytic ocnverter o2 monitring system,hopefully will not trigger the lights to come on.

adam

OBD1 cars shouldn't have check engine lights but I know that most OBD2 cars will trigger a check engine. I carry an O2 simulator that will relieve the problem for OBD2 cars.

Will not trip check engine lights.

I just checked my supercharged roadster, this car has no cats, no mufflers, just straight pipes. I'm going to post pictures tomorrow, it looks well done.

wow no mufflers eitheir,i beleive your gonna need some back pressure,you might also get alot of popping sound when you let of the gas,please keep us posted

adam

I was curious about that too which hesitated me from removing the precats. Now I only have the secondary cats removed with no problems, without the muffler I do get a loud pop on hard shifts. It's really loud even with the precats on without the muffler now without all cats and muffler, that's gonna be insane. I remember someone posting a straight pipe with O2 simulators, are custom tail pipes available to fit properly with the straight pipe? I'm running mine without tail pipes and have pipes running after the precats firing below the car.

I'm running Tubi and no Cats on a 92 (OBD1) - It will NOT give you a check engine light.

 

Re: Popping and Back Pressure

 

Contrary to popular belief, hp gains are from exhaust speed and not necessarily exhaust back pressure. However, the two are usually go hand in hand, but not always. Much is predicated on the pipe/flow design. I withnessed this while hyperflow put my car on their flow bench.

 

How much popping you get will depend on if you have pre-cats or not. Usually precats left on will greatly reduce the popping. On OBD1 it took 3 different exhaust set ups that I personally installed to get the right "balance".

 

BTW - If anyone is interested in OBD1 I have to new (used less than 15 miles ea for testing) cat replacements. Have Tubi straight pipes (has threads for sensors) and a Quicksilver "silenced test pips". It replaces the cats, is free flow, and will not produce any popping - drawback to this unit is it almost sounds stock.

 

PM me if interested...just been too lazy to put them on ebay yet..

Does anyone have any experience with the high flow Gt cats from Larini? Or should I just go with test pipes? Don't want to be tooo loud.

I too would be interested in hearing comments on the Larini high flow cats...

I think they are about $2500... Anyone have them?