Why would I have a smelly exhaust???????

[mybabyM3]

My exhaust has really started stinking bad. I don't know if I have an O2 sensor going bad or bad cats. The car seems to drive fine. I do have decreased gas milage. The OBC says 18.9 mpg whenever driving. Anyone else have or have had stinky exhaust on their Bimmer?

 

[poboyis]

probably cats, does it smell like sulfer/rotton eggs?

 

[mybabyM3]

I don't think it smells like rotten eggs but it does stink badly. I thought with bad cats the performance really decreased. I guess that could be coming.

 

[m5runner]

always go with the cheapest fixes first. Gas/fuel injector cleaner, O2 sensor, check spark plugs and everything else affiliated with combustion. check air filter also

 

[chief]

Do you have black smoke coming from the exhaust pipe? If you do it is probably running rich. If you can check the idle control valve vacuum tube behind the throttle body. It may be split or dislodged causing a leak which in turn causes the computer to add more fuel; hense, the running of additional fuel, and the black stuff coming from the exhaust, in addition to the acrid smell.

 

[mybabyM3]

Chief, I have been told that I do have some black smoke coming out of the exhaust on take off. I will check to see if the tube is the problem. Is there more than one tube? About what diameter is it?

 

[chief]

the hose is about a 1/2" in diameter. It is located under the throttle body toward the block and is attached to the throttle control valve. Unless someone put a band clamp on it, it should be easy to remove and check. You may want to jack the left side of the car up and look at from below.
Good luck.

 

[m5runner]

you don't have to jack the ride up. it's right there infront of you when you open the hood up. mine cracked over time and it caused the car to idle erratically and i just went to Global and replaced it myself. Took me a whole 3 minutes (I stopped for 1.5 minutes to get a few swags of my beer)

 

[mostwired]

>> My exhaust has really started stinking bad.
Take a shower, man!

But also, check your oil and coolant levels. And the air filter.

 

[chief]

Any luck? Just wondering if you found out what was causing the problem.

Keep the faith,
Bill

 

[mybabyM3]

Chief, I found that hose it looks in good shape but there was no clamp at all on it. It is on as far as it can go. Would this still be part of the problem? I have been really really busy with work lately and haven't had the time to get the cat's checked either. I think I am going to put a hose clamp on the hose just to be sure. But yes it is still stinking. Thanks for the check up on the progress.