OK i'm thinking about running a header to test pipe then the factory cat back. My questions are will the factory cat back be to restrictive and a waste of money on the header and test pipe?
Also will it throw the check engine light? I want my car to be quiet so I really dont want a cat back system.
It's a 94 Ls so obd I.
Thanks
I don't think you're going to be quite with a test pipe. Also stock catback piping diameter size is 2inches. I'm not sure how big the inlet size of the stock exhaust manifolds are but I doubt you'll get any "serious" power gains from a bottle-neck set up. Imo, it would be a waste of money to upgrade the exhaust manifold + delete cat and do nothing with the stock mid pipe and axle back.
If you want to be quite + somewhat power gains, fabricate your whole exhaust system so it doesn't bottle neck. (header,cat,midpipe,resonator,axleback-muffler) Make sure the piping doesn't exceed over 2.5 inches if your only upgrades are i/h/e. Add a resonator on your mid pipe (this is crucial to making your exhaust have a more silent tone, you could even add 2 resonators if you like silence :thumbs up). If you want you could get a high-flow cat or fabricate a test pipe, your call bro. I'm not sure if you have smog emissions testing in your state but in cali, cat's are necessary. (legally speaking)
I hope this helped you man. :thumbs up.
