jrt805

Hi, I was wondering if anyone could help me with my problem. I have an aftermarket dual exhaust and the passenger side of the exhaust pipe is blowing cold air. The driver side exhaust is at normal temperature but doesn't smell like its burning fuel. Engine is stock, no modifications. I had a crack on the port for the oil pressure switch and covered it up with some JB Weld epoxy, I doubt it will hold but I'm trying not to spend on a new block right now. Not sure if that could be causing the cold air coming from the exhaust pipe. Does anyone have any idea of what could be causing this? Has anyone else had this problem? If so what was it/ how did u fix it?

XxMerlinxX

Could be a leak in your catback allowing cold air to be pulled into the exhaust stream on the colder pipe. Could also just be the way the stream is divided inside, more exhaust gets diverted one way than the other and that side will be warmer with the other side being cooler. I wouldn't worry about it since it's not really hurting anything.

jrt805

Yeah I was thinking something about the catback or cat converter but lucky no engine codes so far. And the colder side is just cold, no heat coming out, compared to the driver side pipe being hot. Also I'm thinking if it could be an O2 sensor going bad.

XxMerlinxX

Maybe you haven't seen how dual catback systems work? Below is a picture of our factory exhaust. Starting from the left, you have the catalytic converter which attaches to the header that comes off of the engine. The exhaust stream travels from the cat down to that little piece of pipe sticking out, which is a helmholtz chamber, and then hits the resonator, the oval looking can in the middle, before being split off to the two mufflers. So it can't be a bad cat, because that would affect the exhaust flow before it ever got to the split. Also, an 02 sensor wouldn't have any affect on one side blowing cooler than the other either. Something could be clogging/diverting one side or the other at the split, or there must be a leak somewhere near the split or on the passenger side muffler itself.

jrt805

OK I understand what you are saying. are there any tests that can help me Pin point the problem to help narrow it down?

XxMerlinxX

In the event that there's an obstruction, I would try stuffing a rag in the driver's side muffler while the car is running to see if it makes the exhaust warm up on the cold side. If it does warm up, but then goes back to being cold once the rag is removed, I'd get under the car and look for the leak. One way to do this would be to plug both exhausts and then try to listen/feel for where the leak is letting exhaust out. I would certainly inspect the split where the mufflers come together and the back of the muffler that's staying cold.

slalom44

Are you saying one side is cold when you have a fully warmed engine after driving? Is it possible that you're just seeing a temp difference just after start-up? That would explain it.

jrt805

This happens when cold and remains the same after the car has warmed up but is still at idle. I took it out for a test drive after plugging up the crack on the oil pressure switch port but unfortunately it still leaks oil, and smoke from exhaust smells like carbon( hydrocarbons) I'm guessing that this is due to the crack, at this pout I'm convinced that I have to buy another short block.

jrt805

I will have to give that a try and take a look see of what could be causing this. Thanks for the info.

mambo

Hey OP, just wondering if you found what caused this, since I have the exact same problem with my Greddy SE. Driver side exhaust is hot, passenger side is cold. If I plug up the driver side exhaust, the passenger side blows out hot air.