Is it possible to take the stock CAT and ram a pipe down the center of it and throw the peices that come out in the trash and then put it back on and just have it there for cosmetic reasons? I was thinkin about taking off my CAT and seeing what it sounds like and if it sounded good I wasnt going to put it back on or I was going to shove something through it and put it back on gutted? Is this possible?

 

Yes, that is very possible. My cat started to rattle about 2 years ago so i just took a long rod a broke the rest of the ceramic apart and emptied out the cat. i didn't put a pipe through it and it sounds fine. i will say that i have a 3" catback system so it is some what loud when i'm on the gas. my .02

 

Sounds like crap if you just gut it and leave it alone. Either put a pipe through it, or take it off completely.

 

I cant get the darn thing off. The bolts are rusted on and they wont move!

 

id say torch the damn thing...but im not sure if thats totally safe lol :lala:

 

I had to loosen the cat once before, and I had the same problem. I soaked the hell out of the bolts with WD-40 and then I went at them with a big torque wrench. I was really surprised how hard they were on there, but they came off. Be careful though, cause you can break them if you aren't careful. Hell, I'm surprised I didn't break them.

 

i torched mine off, acciendently caught the rubber hang on fire, buddies where standing by car bs-ing, had to go get the water myself.

 

I took a 3" piece of straight pipe and put the heat shield shell around it from the old cat. Looks good when you peek under the car, but won't fool anyone with it on a lift unless they are a complete idiot. Good for the ocasional roadside inspection though

 

Anyone notice a loss of low-end power after removing the cat? I have 3" catback, and no pull untill about 2.5k rpms or so, then the nut kicks in...

 

I can't say, because I converted to TPI, added headers,3" exhaust, ported TPI heads with a 3 angle valve job, and stuck an LT1 cam in all at the same time, and am using the apyp bin. It definitly has way more low and high end grunt than the L03 did with just the 3" cat-back, and pulls hard right up until it smacks the rev limiter at 6K. It does have more after 2K, but it's hard not to break the tires loose off idle. If emissions ever come here, I guess I'll find out though.

 

I have pipe with converter ends welded on and it is the same length as the converter for a bolt in. My car is an 83 LG-4 and with the converter which was original until 2 years ago you could stick in neutral and try to rev the motor and the tach would move so slow. Now it pulls hard and tach actually moves quite a bit faster. The throttle response is a lot better too, with the addition of a Flowmaster which sounds great.

 

I put a piece of pipe inplace of my cat with the flange from the cat welded on one end. Overall performance improved and throttle response ie acceleration was noticeably better.
If I needed to have a cat to pass a visual inspection I think I would just knock the ceramic honeycomb out. I dont believe the difference between this and fitting a pipe would be much.

Simon