Dangerous Catless Smell Driving

[coconutboy]

I took this screenshot because Tapatalk wouldn't let me load the video I originally took. Anyways my exhaust system (UEL catless headers, high flow fp & custom catback) is being vacuumed into the car via this bar (right behind the rear bumper) and in turn coming into the cabin while driving with windows down. Anyone know what I should do? Cars naturally have holes to release air but this is not safe to drive in. I blasted the AC, closed all windows and closed my garage door with car off, hovered a cigarette around the bottom of car to see what made smoke move this most, and by far this bar had the most movement. I also put a little trees car fresher in my spare tire well and my whole car smelt like the "Black Ice" scent when I rolled the windows down. Any help is much appreciated. My chest gets tight when driving. This doesnt happen with a stock fp only high flow fp. Thank you!!



Sent from my SM-G950W using Tapatalk

[DarkPira7e]

Logically it makes sense to use the stock front pipe then. If a modification causes you discomfort, take it off.

[coconutboy]

Originally Posted by DarkPira7e

Logically it makes sense to use the stock front pipe then. If a modification causes you discomfort, take it off.

I totally agree. However, the car doesnt sound that good without a high flow fp, and here's the thing. The point of an exhaust system is to get all exhaust gases from the engine, to the rear of the car. However, I am the only one with exhaust smell actually being rerouted back INTO the cabin when driving windows down. In a perfect world you only smell it at when stopped.

Sent from my SM-G950W using Tapatalk

[DarkPira7e]

Originally Posted by coconutboy

I totally agree. However, the car doesnt sound that good without a high flow fp, and here's the thing. The point of an exhaust system is to get all exhaust gases from the engine, to the rear of the car. However, I am the only one with exhaust smell actually being rerouted back INTO the cabin when driving windows down. In a perfect world you only smell it at when stopped.

Sent from my SM-G950W using Tapatalk

Maybe your exhaust system is allowing some gas to leak by a flange then? You should get it smoke tested

[coconutboy]

Originally Posted by DarkPira7e

Maybe your exhaust system is allowing some gas to leak by a flange then? You should get it smoke tested

I'm skeptical it is, so let's say hypothetically it isnt. What do I do? Lol I'm dooped

Sent from my SM-G950W using Tapatalk

[humfrz]

Originally Posted by coconutboy

I'm skeptical it is, so let's say hypothetically it isnt. What do I do? Lol I'm dooped

Sent from my SM-G950W using Tapatalk

Maybe it's like what happened to certain police SUVs, that some holes were allowing exhaust fumes into the vehicle. If that's the case, I'd suggest you plug up any suspected holes around the rear of the car.

OR, find and fix the exhaust leak.

OR, extend the exhaust system -

[Sapphireho]

Originally Posted by humfrz

Maybe it's like what happened to certain police SUVs, that some holes were allowing exhaust fumes into the vehicle. If that's the case, I'd suggest you plug up any suspected holes around the rear of the car.

OR, find and fix the exhaust leak.

OR, extend the exhaust system -

That's at Laguna Seca. Point it infield.

[Irace86.2.0]

Originally Posted by coconutboy

I'm skeptical it is, so let's say hypothetically it isnt. What do I do? Lol I'm dooped

Sent from my SM-G950W using Tapatalk

You have an exhaust leak, or you just aren’t familiar with catless cars. Ever been around or inside a classic car? It isn’t good. It is why we have catalytic converters. The irony of you saying it is not safe to breathe after removing the cats is kinda hilarious.

[Brz866]

I'm fully catless and get the occasional whiff of fumes from wind but not to this extent and I never touched the holes you're referring to. Look for black carbon deposits leaking from the flanges. If you can't hear it you'll see it. You also say custom catback so any manor of weld defects or uneven flanges is a definite possibility.

[NoHaveMSG]

This is his second thread on this issue. He ignored the advice in the first thread.

[Grady]

Originally Posted by NoHaveMSG

This is his second thread on this issue. He ignored the advice in the first thread.

We should quit giving him advise. The problem will fix itself. Darwin was correct.

[NoHaveMSG]

Originally Posted by Grady

We should quit giving him advise. The problem will fix itself. Darwin was correct.

LOL right? It's weird how they keep having to use ultra copper to seal exhaust gaskets, but then later on the smell comes back

My friend who's a technician at Subaru said to take out the headers and put copper silicone on gaskets for a full seal.

Update:

There was black soot on the gaskets.

My guy said the gaskets aren't that good even though they came with the header.

Hes working on the car now.

Will give update later

Update:

No more smell unless coming to a stop or reversing! (This is expected)

Thanks to everyone that commented.

Mechanic put some gasket sealant on the headers to block, headers to overpipe and overpipe to fp.

Update...

Smell vaugely came back into cabin.

[DarkPira7e]

Originally Posted by NoHaveMSG

LOL right? It's weird how they keep having to use ultra copper to seal exhaust gaskets, but then later on the smell comes back

I'm not sure what it is about the internet where people who don't get the answer they want to hear just keep asking differently, hoping they'll find someone who gives them something they want to hear.

[NoHaveMSG]

Originally Posted by DarkPira7e

I'm not sure what it is about the internet where people who don't get the answer they want to hear just keep asking differently, hoping they'll find someone who gives them something they want to hear.

They like the easiest answer.