Fume smell E92 M3

[indya8]

Hey guys,

I have a 2013 M3 it is stock but i now have the acm mod done. I get a fume smell on cold starts, it does not come into the cabin. Just smells from the outside. My cars engine light is on with a message that says "increased emissions". The error is for a o2 sensor. Think the smell is linked to it?

[wheezyF]

I had the increased emissions light come on shortly after I deleted my secondary cats but they went away after a couple starts later and never saw again lol.

My car definitely smells more on cold starts than before I modified the exhaust, but not really noticeable once warmed up

[timothy2001]

I have never heard of the OEM or ACM exhaust mod causing an increased emissions light or set a code. I have the mod and never had an issue with it. It may just be a bad O2 sensor.

[nekbreaker]

Originally Posted by wheezyF

I had the increased emissions light come on shortly after I deleted my secondary cats but they went away after a couple starts later and never saw again lol.

My car definitely smells more on cold starts than before I modified the exhaust, but not really noticeable once warmed up

your secondary cats have no sensor so they will never trigger a cel light

[tdott]

It runs rich on cold start up to heat up the cats faster, maybe that is what you are smelling.

[wheezyF]

Originally Posted by nekbreaker

your secondary cats have no sensor so they will never trigger a cel light

Yea I figured. But strange timing that it happened right after it was removed lol

[indya8]

Originally Posted by tdott

It runs rich on cold start up to heat up the cats faster, maybe that is what you are smelling.

Ahhh gotcha. Thanks man!

[///M Power-Belgium]

[nekbreaker]

Originally Posted by wheezyF

Yea I figured. But strange timing that it happened right after it was removed lol

they may mess up your o2 sensor which are all in the primary cats