01 M3 Pending Codes : Need Help
I couldn't complete my emissions test due to all my monitors being set to "not ready." but my car seems to be running fine. So I borrowed a OBD II reader from a good friend to see if I could get more information. It turns out that I have three pending codes:
1) P0101 Mass or Volume Air Flow Circuit Range / Performance
2) P0172 System Too Rich (Bank 1)
3) P0175 System Too Rich (Bank 2)
I pulled my intake tube, air filter, and maf out. It turns out my air filter was really really dirty, but my intake tube and maf looked as if they were still new. I replaced the air filter with a K & N and cleared the three pending DTC codes. I started my car up with the OBD II still connected as per the manual to see when the drive cycles were completed. Half way down the hill I live on my RPMs started jumping from 500 to 2k continuously until my car finally stalled. I started it back up without the reader attached and it was doing the same thing for a minute until it stabilized. I then pulled out when my car almost died again. I was able to keep it running and pulled into a parking lot when it looked like a there was a decent amount of smoke coming out of my exhaust. As soon as I got in the parking lot my car was running fine and I was able to turn around and make it all the way back home. As soon as I got home I checked my computer for codes and found that 1 pending code existed.
1) P0175 System Too Rich (bank 2)
I again cleared the codes and this time disconnected the reader. I started the car letting it idle for a while and proceeded to try and drive up the hill. This time there was no craziness with the rpms this time however it appeared my car was misfiring especially when I shifted into second gear. When I got back home after like a 3 minute drive no codes were thrown.
So I am unsure of where to go from here? Is there a proper way to clear pending DTCs? What are some things I should check? My car only has 33k miles on it if that matters.