- This topic has 0 replies, 1 voice, and was last updated 5 years, 5 months ago by
.
-
Topic
-
Hey all,
To begin with, I’ve had some experience resolving P0420 codes before. I know the cat is usually the culprit. I’ve watched all the videos, gone through the O2 sensor data, and I’m still stumped. My friend’s Focus has about 80,000 miles on it. It has been in for the evap recall work and transmission recall work.
With the car warmed up and the fuel system in closed loop, the upstream O2 sensor switches between 0 to 0.2 volts and about 0.6 to 0.8 volts. The downstream sensor hangs steady at around 0.5 to 0.7 millivolts, staying closer to 0.6 and 0.7 consistently.
The car throws P0420 intermittently, but as far as I can tell, the data suggests the catalyst is working ok. There are no other codes stored or pending in the OBD II memory. LTFT and STFT are well within spec. I saw nothing else weird while viewing the data on the scan tool. This is a flex fuel vehicle, and my friend does run ethanol. The scan tool showed about a 55% alcohol content. I don’t know if that matters. I’ve never dealt with this on a flex fuel vehicle.
Am I missing something? Anything?
Thank you.
- You must be logged in to reply to this topic.