[KjPerry]

So I bought my 2016 M235i xdrive this last year. I live in IL and have to do emission testing. When I bought the car, the previous owner had already installed a catless downpipe. I have also bought a Remus throttle controller.

When I went to go do emission testing, my car is throwing two errors which caused me to fail.

The two trouble codes are P0420 (catalyst system efficiency below threshold) and P00BD (mass or column air flow).

From my understanding when you tune the car with BM3, you can check a box that your car has a catless downpipe and will no longer throw that code. Can BM3 "trick" the car into not throwing these two error codes and in turn pass IL emission testing?

I plan on emailing BM3 as well but any feed back on this is helpful.

Thanks in advanced.

[khj24]

Originally Posted by KjPerry

So I bought my 2016 M235i xdrive this last year. I live in IL and have to do emission testing. When I bought the car, the previous owner had already installed a catless downpipe. I have also bought a Remus throttle controller.

When I went to go do emission testing, my car is throwing two errors which caused me to fail.

The two trouble codes are P0420 (catalyst system efficiency below threshold) and P00BD (mass or column air flow).

From my understanding when you tune the car with BM3, you can check a box that your car has a catless downpipe and will no longer throw that code. Can BM3 "trick" the car into not throwing these two error codes and in turn pass IL emission testing?


I plan on emailing BM3 as well but any feed back on this is helpful.

Thanks in advanced.

No, you pretty much have one option and that is to reinstall a downpipe that will pass emissions, whether thats the stock downpipe or aftermarket catted ones that guarantee no CEL. Fabspeed and AA, think ~$1300. BM3 only hides the code by permanently leaving them "Not Ready".

[BostonM235xi]

Have to replace with stock cat for emissions inspection. BM3 will hide CEL but still show not ready.

[Liandri]

Off topic, but careful with the throttle controller if you have an 8at. Iirc read in an 8hp thread that it uses the accelerator pedal position sensor as one of it's primary inputs to determine line pressure or clutch clamping force and it was said you never want to modify that signal outside the dme. 6mt obviously doesn't matter

[KjPerry]

Thanks for the feed back guys. Greatly appreciate it. Going to turn off my throttle controller for awhile.

My brother lives in IN. Maybe I'll just register the car in Indiana haha.

[js0228]

KjPerry, (I live in MD) I have catless installed on my car as well and I've also failed the emission test before but passed it after they told me to come back after I think 8days? When I first went in I had my car with JB4 and MHD BEF set at map5 no CEL because I would always clear it from my car, but the machine couldn't read my ecu I guess so it failed. After the first time it failed I changed my map to 0 and drove it around for 8 days or 2 weeks and went back with no CEL and passed the emission test still with catless down pipe. I think it failed the first time because it was at map5 maybe.

[hardparker]

I passed emissions a week ago on my FBO X3 using a CatSim. I was on the OTS stage 2 91 octane tune with the map config set to enable catalytic monitoring.