I have a '99 Ls with a JRSCer pulling 7lbs of boost.
Two weeks ago I put a custom made straight pipe in place of the stock cat. and got very good results power wise and recovered 2 more psi for a grand total of 9psi, but now the car stinks really bad like burnt oil/fuel.
Also my Greddy makes a nasty pinging sound (sounds like pins in the muffler)at high RPMs.
If I put a aftermarket performance cat on in the straight pipes place will I loose any power or boost and will it clear up that smell and pinging sound?
When I had the Greddy exhaust,Kamakazi 4-1 header, the supercharger and the stock cat on it sounded so clean and sweet but was only able to put out 7psi Max.
Now it's just LOUD and Stinky.
Will a performance cat fix all of that or do I just need to settle for noise/smell for performance.
Do you have any certain cats to recommend?
Thanks, -Jeff

 

You can get a Carsound cat off eBay for about $50. Take it to your local muffler shop and have flanges put on it and an O2 sensor bung. It's a compromise between a stock cat and a test pipe.

 

Ebay haaa,
Sweet, thanks for the lead.
-Jeff

 

The smell is because the cat breaks down the oil/residue, without it, that shyt just shoots off.

 

my friend has a 5.0L mustang and he went all header for awhile, damn that bitch was loud. then he put on an x pipe without the cat n muffler and it was still pretty loud but still making that pinging noise you described, now he put the high flow cat and muffler on and it sounds much better...