ChrisB

After a dozen runs of hard acceleration, There seems to be an odour comming from ther exhaust.

Some one once posted that it is had something to do with too rich of a fuel mixture and somehting to do with the the catalitic converter.

Can any one explain this better to a non mechanical guy like me?

Is it bad for the car? Should I not do the quarter mile + flat outfor fun time after time like that?

Should I report it at the next regular service?

Bigdot

its your cats man.

after a while you wont have any power and it will smell like crap always.

better change them!

HLG600

Mark's right, that smell correlates to a problem with your catalytic converter. But don't worry, you now have an excuse to put in higher flowing ones.

Pigzmickey

Right on!

ChrisB

Will the normal MB maintenance take care of this?

You guys seem to imply that "free-er" flowing catalytic converters will improve performance.

Does that mean other than MB equipment?

Lincoln

The smell doesn't necessarily mean you have bad cats, it can be caused by high sulfer content in the fuel. I wouldn't run out and change the cats unless you are experiencing some of the "other" symptoms that they are going bad like reduced performance or worsening gas mileage.

ChrisB

Thanks for the tip.

Performance is fine.

Under "normal" or reular lead foot driving there is no smell.

The gas mileage is fine also.

kerrypacker

That's right Lincoln, Under major power take offs I get the smell also and my cats are brand new free flows just done last August. My opinion is its the sulphur in the gas. I can see that Chris B lives in Canada. So do I. Its the gas Chris

ChrisB

I have smelled this only twice. Once last summer and once this spring.

Both times I had gone nuts doing nearly back to back 0 to 125 mph maximum acceleration runs. Say 10 runs of that punctuated only with with foot to the floor cruising arround a large park property between the runs.

Very heavy driving both times over a 30 to 45 minutes span of time. Pretty smelly at the end of that punishing treatment!

From what you say, I would guess that it was the driving & maybe something to do with the quality of gas in Canada.

dafi129

Cats don't go on 99 cars...
SL's from 1990 still have the original cats on....
It's probably the fuel.......

Zahermurad

I just took my 2014 GL to the dealer for the bad smell. There is an article about something leaking from the engine. They had to reveal it and Ionia the interior of the car. It's a known problem now. I am just curious if I have been driving my car for a year with deadly fumes in the cab. Anyone knows?

Stuart_Dands

Cars prone to short journeys, low rev and Low mileage use, if given some right foot heavy use now and then will smell a bit. As already said though, unless other symptoms are experienced or it is smelling bad all the time, I would not be rushing out to buy new cats!!