I recently bought a megan catback, and I installed it a few weeks ago. It sounds great, but there's this weird sputtering coming from what sounds like the cat and the straight pipe for the catback. The guy I bought the exhaust from (yeah its used) had some parts and some gaskets he had made from some gasket material he got from autozone. I asked him if the gaskets were still good, and he said he never had any problems. So far, the only things that seems to be happening is the sputtering that I only hear during idle that is coming from between the cat and the straight pipe, and my car seems to feel slower. It doesn't pull like it used to, but that doesn't make sense to me. I don't see how a possible exhaust leak could ever cause any kind of power loss. A friend had helped me install the exhaust, and we had a hard time tightening down the left bolt on the connecting piece from the straight pipe to the cat. He got it on as best as he could (better than I could) and it seems tight. I don't see any gaps, and the car seems to be running fine except for what feels like the power loss. I'm stumped. Any ideas?

 

Your car needs a tune, contact TTP Engineering and he will hook you up

 

I don't know what to say, except thats the reason why I don't buy used **** like exhausts. Go buy some new gaskets. Try that, that's the cheapest solution. If that doesn't work put your stock exhaust back on.

 

maybe its an exhaust leak, the one on my greddy ti was pretty busted, sounded really raspy, jack up the car and use like a cigarette or something the produce's smoke to check for an exhaust leak if you cant feel it, if you need gaskets i would try napa or get some rvt, its like this silicone gasket maker i used this with a gasket and my exhaust is nice and sealed now

 

As far as the car needing tuned, NO! But too feel the gains you will. I would get some high temp RTV like stated above and seal off all flanges with it and retighten everything. I used it on every flange as BR Exhaust didn't use gaskets

If the car is sputtering and not the exhaust, pull the plugs and give them a look.

 

I reuse my exhaust gaskets. To seal them off I use Permatex Copper Sealant between the gaskets. Before, I used to have the sputtering due to exhaust leaks. It hurts your performance, especially when they tune it with a wideband. After that, I don't have the sputtering after using the sealant.

 

most likely an exhaust leak. i had trouble with that part of my exhaust too. if they had use 3 bolts on that flange, or had added one more exhaust hanger, i don't think it would have been an issue, but it sags just enough to make it hard to torque them down hard enough to seal them there.

like whoang40 mentioned, i used copper exhaust sealant as well.

do you smoke cigarettes? it's an odd question, but the leak i had was kind of small and couldn't really be felt with my hand. so i lit up a cig, crawled under the car, and blew smoke around until i saw it getting blow around by the leak

 

Great idea!

You should fix any exhaust leaks. Vibrant makes many 3" 2 bolt flange gaskets.

 

Wow thanks guys. I'll try the cigarette thing, even though I don't smoke. Yeah the flanges were cut from something he got at autozone, he traced it out the cut it. I should've just bought new ones, which is of course my fault. And buying the exhaust used, again my fault. I bought it from a guy who used to post here, he was debating whether he should keep it or sell it, since it used to be his dad's. He ended up selling it and had the exhaust left over. I found it on craigslist, and got it from him. That's when I found out who he was. What a small world. Oh yeah, we had to buy new bolts, washers, and nuts because he didn't have all the hardware. This probably isn't any kind of cause to my problem though.

 

Your right his car does not really need a tune. I read through his post quickly and thought he had a straight pipe with no cat and the car was sputtering at ilde. I went back and read it again and he has a exhaust leak. My bad. But a tune would still help bring the car to its potential.

 

I was listening to it again today and it definitely sounds like it's coming right from the flange between the cat and the pipe after the cat. I had a friend of mine listen to it too, and he agrees, and he was on the other side of the car. How small of a gap can cause a leak? I can't see any gaps, it looks like its tightened down pretty well on the gasket. The bolts we used were too close to the exhaust though, so it was hard to tighten it down right from the start of installing the catback. I guess I'll have to keep looking, and try new gaskets. Thanks again guys

 

u could also try a flat pieace of cardboard and grab a freind

smother the exhaust with the cardboard and have ur friend listen and feel the connections for exhaust leaks, it should be alot louder because its forcing it threw the leaks