[Burrlap75]

So I have been noticing the rotten egg exhaust smell from my car when I put load on it like going up a long hill or accelerating hard. I currently have 80,000 miles. Its 2016 340 with Stage 1 bootmod. Any suggestions on how to remedy the problem? Gonna change the plugs to see if that helps.
Thank you

[leew102]

Originally Posted by Burrlap75

So I have been noticing the rotten egg exhaust smell from my car when I put load on it like going up a long hill or accelerating hard. I currently have 80,000 miles. Its 2016 340 with Stage 1 bootmod. Any suggestions on how to remedy the problem? Gonna change the plugs to see if that helps.
Thank you

Could be a clogged cat

[Wires]

Have you checked for any codes? Rotten egg is something misbehaving which messes up the emissions.

[Burrlap75]

I have no codes, and the car seems to run fine, plenty of power. Would a clogged cat sap some power?

[F30_Paul_]

I have 88,500 and I have rotten egg smell and Catalyst Efficiency Below Threshold error code twice. Just bought a like-new cat. My having too much fun with MPPSK probably melted my cat.

Your best bet is to buy another cat before it becomes a bigger problem.

[leew102]

I had a similar rotten egg smell after less than a year on the CTS catted downpipe. Threw no errors because the tune coded out the CEL. Power was slightly less, but nothing you would realize in day to day. When I took it off, the cat was melting together, replaced with an AA dp and smell was completely gone.

[AndrewC1989]

A rotten egg smell is indicative of a failed/failing cat. Changing the plugs won't do anything, your tune melted your cat core most likely. Get a high quality HJS sport cat from a company like fabspeed and you won't have any issues.