Hello there!
I have been reading for hours on the P420 code as my 2008 Subaru Forester with 287,000 miles is throwing it now. I am thinking of trying to replace a sensor, not sure which O2 sensor to try to replace first. I have limited funds so can't really afford to have a mechanic charge me diagnostic money...which would probably be enough to pay for the sensors anyway. It almost seems as the comments are saying it's more often the rear one. Thoughts?
Through my reading, I have noticed the following from a post started over ten years ago. :nerd:
I am also getting a cylinder one misfire - ONLY WHEN IT RAINS - could this P0301 code be causing the P0420 code. I have replaced the coil pack and the spark plugs, which caused it to run good again, but that same problem has slowly come back to haunt me.
Looking to hit the 300,000 club, so any help or advise to get me through another 13,000 miles would be greatly appreciated! :grin2:
I have been reading for hours on the P420 code as my 2008 Subaru Forester with 287,000 miles is throwing it now. I am thinking of trying to replace a sensor, not sure which O2 sensor to try to replace first. I have limited funds so can't really afford to have a mechanic charge me diagnostic money...which would probably be enough to pay for the sensors anyway. It almost seems as the comments are saying it's more often the rear one. Thoughts?
Through my reading, I have noticed the following from a post started over ten years ago. :nerd:
I haven't been able to find out what the "mechanical fix" is. Can anyone give me any insight?"I've be battling this code too (P0420) since the beginning of this year (car currently has about 140k miles). First there were two codes (forgot the other one, it was related to the rear sensor), so I replaced the rear sensor, but P0420 is still there once in a while. I kept on resetting it and it behaves exactly like others have described: it comes back, sometimes weeks, sometimes months. It looks like the cat converter is at fault in my case.
I'll try the $5 fix (mechanical fix) first."
I am also getting a cylinder one misfire - ONLY WHEN IT RAINS - could this P0301 code be causing the P0420 code. I have replaced the coil pack and the spark plugs, which caused it to run good again, but that same problem has slowly come back to haunt me.
Looking to hit the 300,000 club, so any help or advise to get me through another 13,000 miles would be greatly appreciated! :grin2: