RiceEatingWS6

I had the loudmouth modular catback put on over a year ago and loved the sound. I've since put on my pacesetter lts and a texas speed ory, but the car was ridiculously loud and raspy with the loudmouth resonator so I put a magnaflow straight through muffler on it which has quieted it down a bit but it still really raspy especially when downshifting. Another thing I noticed is that I seemed to have lost alot of low end power. A couple of guys at my job said that by getting rid of the cats and having no restrictions, you lose backpressure and low end power as well as having alot of drone/rasp. I'm also noticing that when I step on the gas and let off around 2500 rpm there's like a coughing/crunching sound underneath the car which wasn't present before. I had all the work done at an exhaust shop, and from underneath there doesn't appear to be any leaks. I'm almost ready to put some cats on there cuz the car is running and sounding like sh*t. An ASE master certified mechanic also told me that the rear O2 sensors do more than just tell the PCM that the cats are working which is contrary to what people have said on here.. They are both responsible for monitoring air fuel ratios and adjusting long term fuel trims, which makes sense because my car is also running very poorly since removing the rear O2s.. Any advice you guys could give me would be appreciated.. thanks..

sixvi6-camaro

iTrader: (9)

Rear O2's have nothing to do with it imo. What the car needs is a tune. Some cars run rich after Long tubes are installed, others run lean. Either of which would cause a loss in power.

As far as the rasp use a quieter exhaust or add cats or forget the y pipe and go true duals. No cats with a Y pipe and long tubes = rasp.

jond99

iTrader: (1)

+1 for getting a tune.

corvet786c

iTrader: (6)

I have the LM exhaust and pacesetter headers and catted y from TSP too. What I did was take the car to a muffler shop. They heated the y pipe from driver side and lowered it about 4 inch. No banging, also they disconnected rear o2. Still, the car running pretty good, no issues, though I still want to put the o2 on again when I get some xtra $

RiceEatingWS6

They lowered the ypipe 4 inches or 1/4 inch? Have you had the car tuned since you disconnected the rear O2s? How does your exhaust sound with the catted ypipe? I actually have the TSP ORY with no cats and it sounds like sh*t even after I swapped in a magnaflow muffler for the Loudmouth resonator..

mongoose_ss

have you tried rear o2 simulators?

gyrene2003

ive got pacestters, tsp catted-y and LM1 on my car and think it sounds really good. i know with cats i may have lost like 3-5 ponies which i still find hard to believe cause the cats are really just bigger pipe with 1 screen in them o baffle sound, i looked through them with a flashlight before i installed. at start-up the car is noticably meaner, but at idle its almost the same as just catback LM, but at wide-open throttle its awesome. i still have some rasp but im not to picky and figure ive got a good setup so ill deal with alittle rasp. On the other hand i had a friend who had pacesetters with an ORY and LM1 on his car and it was STUPID loud! I know what ya mean man, it was unbearable even for me and i love loud cars!