I just installed banks monster cat back on my 98 i6 and noticed a relatively loud backfire sound when im in gear but let off the gas. My exhaust manifold is cracked and on the list this summer to replace but i never got the backfire noise with stock exhaust? Could it be somethings not tightened? I tightened it all down real good.. Tge noise isnt from the end of the tailpipe but from under the jeep. What would cause this and why? Thanks in advance
06-10-2013 08:52 PM
Well, it's pretty apparent that you have an exhaust leak that you're going to have to find. Which is why I suggested so strongly in your earlier thread that you just have a local muffler shop create & install your new cat back. Cheaper, same quality, no problems. :)
06-10-2013 08:57 PM
U sure isn't just backpressure with aftermarket exhaust you'll get a crackle letting off the gas or down shifting
06-10-2013 11:01 PM
Hahah i know its a good idea but i liked banks and it was stainless but i may need to go to the local place now and see about that manifold. It could be backpressure from exhaust but its a little loud to be backpressure. Def sounds like a leak. Ive heard of people welding over the crack in the manifold, is this an ok idea since its probably considerably cheaper than replacing the exhaust manifold? Or should i just go ahead and replace it?
Oh and on the drive home from work today i tried to replicate the sound and could only get it to happen when downshifting into a high rpm, didnt happen (or at least not loud enough for me to hear) when downshifting regularly. But downshifting to 3rd at 4ths cruising speed it was very clear and loud
06-11-2013 07:09 PM
I have trouble with the ball flange on the banks muffler sealing with the stock pipe end. You can see the black soot lekaing out. Had to add high temp sealer there and I think it's still leaking a tiny bit. I can't tighten it any more either, not the most high quality system I've come across :(
06-11-2013 08:32 PM
Wow i was just about to order this system today. Guess not now.
06-11-2013 09:02 PM
I think I'm a rarity as most reviews are positive about this system (that's why I ended up with it in the first place ;) )
06-11-2013 09:49 PM
Yeah the reviews sound good. But digging around on some other forums i found more people with a similar problem with this exhaust. Mostly though they have leaking problems where the tail pipe clamps to the muffler. Said using RTV High temp copper sealant fixed the problem. Also make sure those slits in the pipe are fully tightened together. One guy said he had to get new clamps because the ones supplied would not tighten to the 35 lbs.
Seems to me this might just be a quality control issue, that or the good reviews come from people welding them on.
06-11-2013 10:27 PM
35 lbs? My instructions said 10 lbs but didnt seem right so i did a bit more.... Maybe i should try some of that sealant..