Hi all,
I got some great info from previous posts on this topic, but I haven't been able to crack my problem yet. I'm hoping you all can help.
2002 M3 w/ 68K miles. CEL intermittently comes on, throwing the P0420 and/or P0430 codes. Also the "Rich to Lean sensor threshold voltage" is failing its test.
Engine temp stays within the 180-187F range. Attached is O2 sensor data for a cold start, as well as a 10-min drive cycle during which the CEL came back on.
To me it looks like the O2 sensors are working fine and the cats are doing okay at idle. However at highway cruise, the post-cat O2 sensors are drifting a lot. Does this indicate failing cats? Should I be suspicious of anything else?
Thanks in advance!
I got some great info from previous posts on this topic, but I haven't been able to crack my problem yet. I'm hoping you all can help.
2002 M3 w/ 68K miles. CEL intermittently comes on, throwing the P0420 and/or P0430 codes. Also the "Rich to Lean sensor threshold voltage" is failing its test.
Engine temp stays within the 180-187F range. Attached is O2 sensor data for a cold start, as well as a 10-min drive cycle during which the CEL came back on.
To me it looks like the O2 sensors are working fine and the cats are doing okay at idle. However at highway cruise, the post-cat O2 sensors are drifting a lot. Does this indicate failing cats? Should I be suspicious of anything else?
Thanks in advance!