No, this thread is not about a runaway feline...but first some backstory:
About a year ago, I noticed that the Croma (2.2 liter petrol, shy of 130 000 km on the odometer) was running rich and it turned out to be a leaky fuel injector which I have since replaced. However, it might have gone too long running rich, which I suspect have damaged the catalytic converter.
It now throws a P0420 error, catalytic converter efficiency below threshold. I have cleared it and it comes back. I graphed the pre- and post-cat O2-sensors (at idle and 2500 rpm, warm engine) and it looks like the post-cat sensor oscillates in tune with the pre-cat sensor, which is a bad sign right, should be flatlining?
Could this indicate anything else than an upcoming cat replacement:bang:? See attached image (RPM: blue line, pre-cat O2 sensor: red line, post-cat: green line).
Thank you in advance
About a year ago, I noticed that the Croma (2.2 liter petrol, shy of 130 000 km on the odometer) was running rich and it turned out to be a leaky fuel injector which I have since replaced. However, it might have gone too long running rich, which I suspect have damaged the catalytic converter.
It now throws a P0420 error, catalytic converter efficiency below threshold. I have cleared it and it comes back. I graphed the pre- and post-cat O2-sensors (at idle and 2500 rpm, warm engine) and it looks like the post-cat sensor oscillates in tune with the pre-cat sensor, which is a bad sign right, should be flatlining?
Could this indicate anything else than an upcoming cat replacement:bang:? See attached image (RPM: blue line, pre-cat O2 sensor: red line, post-cat: green line).
Thank you in advance