Exhaust smell in cabin; APR DP with cat

[VancouverGTI]

This winter I've been smelling exhaust in the cabin, and a co-worker I recently gave a ride to made the same observation right away. Very obvious when idling in traffic, but not an issue when the car is mostly in motion.

I had the shop that installed my APR downpipe double-check everything, and they found everything to be snug, with no signs of soot at either the turbo or the connection to the OEM catback section. They're guessing that it's the low cell count of the high flow cat, and my exhaust getting sucked back into the cabin when it drifts back to the front of the car when I'm sitting at lights.

The smell does go away if I turn off the Climatronic, and is greatly reduced if I switch to recirculation A/C mode (but that fogs up my windows when I turn it back off).

Still... I don't remember having this problem last winter, and I had the same setup then.

Anyone else getting noticeable exhaust fumes in the cabin while running a high-flow cat?

 

[Cryptic1911]

you have an exhaust leak somewhere for sure. fumes don't just enter the car for no reason

 

[white4dr]

I had the same thing happening. It turned out to be the connection between flex pipe and the pipe with the cat. Let your car idle for a minute than open the hood, if you can clearly smell exhaust in the hood then you have a leak.

After a year of not smelling anything, I am getting a very faint smell in the car at idle. I've come to the conclusion that the only way to completely solve exhaust leaks is welding everything

 

[langer]

I had the same thing happening. It turned out to be the connection between flex pipe and the pipe with the cat. Let your car idle for a minute than open the hood, if you can clearly smell exhaust in the hood then you have a leak.

After a year of not smelling anything, I am getting a very faint smell in the car at idle. I've come to the conclusion that the only way to completely solve exhaust leaks is welding everything

You probably have a leak. I have a 42dd with cat and smell nothing at idle.

 

[PRND[S]]

What other mods do you have? I had a BSH competition catch can that had a hose connection melt, causing a leak under the hood that caused fumes to get sucked into the cabin. When the sun was low I could see smoke rise from under the hood.

 

[josein06gli]

Leak, that's why I welded my catback to my downpipe and shits solid.

 

[VancouverGTI]

Thanks for the feedback, guys! I'm convinced; something's not right.

Yeah, welding would be a natch, but I'm going to need to swap downpipes to pass emissions at some point.

PRND, as it happens I, too, have a BSH Competition Catch Can, which I installed this summer. Where did your hose get melted? I'll have a look tomorrow!

 

[PRND[S]]

A piece of the hose that was right above the turbo melted. After the second time I got rid of the BSH and got a Forge.

 

[John/Cue\Publik]

Check for soot around where the dp and turbo mate. If yyou didn't toque it right you may have burnt the gasket

Sent from my HTC Evo 4G Shift using Tapatalk

 

[PRND[S]]

Also, laser pointers are quite useful for detecting the source of exhaust leaks, they make it very easy to see floating particles.

 

[Callsign_Jester]

vband all the things!

But yeah, it's a small leak from somewhere twds the front of the car. Good luck.

 

[Monkeykungfu]

Also, laser pointers are quite useful for detecting the source of exhaust leaks, they make it very easy to see floating particles.

I nominate this as tip of the week! Never thought about that before. :thumbsup:

 

[VancouverGTI]

^ +2! That's a great idea!

Aaaaand, I've found the problem. Where your hose melted, mine just plain came off the brass 90º bung that screws into their intake.
:mad0259:

I remember thinking, "There should surely be a hose clamp on this?" when I installed it, but the instructions said it wasn't necessary. Should've trusted my gut!

I think BSH needs to rethink their lack of hose clamps with their catch can kit. This is the second time I've had a hose come loose on the thing.

Anyway, thanks very much for the help guys! It was a simple fix, but your suggestions had me looking in the right place. :thumbsup:

 

[adamgti]

Also, laser pointers are quite useful for detecting the source of exhaust leaks, they make it very easy to see floating particles.

I kinda want to have a leak now so I can use this tip.

 

[xola3que]

Do you have VTA catch can? Might not be even be the exhaust that's leaking.