[suntong365]

So my car is 2018 m2 with the n55 engine,I got an catted downpipe from vrsf which triggers CEL. At first I tried to use the catsim from ••••74, I have tried 3 different one but it didn't work. I choose to install the catsim on the harness side, so I cut the yellow wire. now I am getting a MHD tune(stage 0 with the function of suppressing the after-cat o2 sensor),but my CEL is still on, btw I just disconnected the catsim and reconnect the yellow wire. But the CEL is still there. Quite annoying! My question is if I want to use MHD to disable the o2 sensor, should I tick or not tick the OEM/catted dp option? Do you think my engine harness or Ecu is damaged or not? Graph attached, Sorry for my bad English and thx for help![IMG][/IMG]

[cecaa850]

Are you sure your O2's are plugged in all the way at the harness?

[suntong365]

Originally Posted by cecaa850

Are you sure your O2's are plugged in all the way at the harness?

not sure，but I just replug the wire yesterday