Huckster Posted January 17, 2020 Share Posted January 17, 2020 Brought it in to Subaru dealer told me it needed a 02 sensor. Replaced. Code came back and then they told me cataliyc converter. Replaced. Code came back. Started checking on line videos and found 1 that showed me how to check wires coming from the ecm to the o2 plug in. I have the power. When I check for ground. Nothing. Ohmed out the wires going to the ecm and they seamed to be fine. Changed ecm and still nothing. Asked subaru dealer if I could get the wiring for the ecm. Told me it was for them and not for the public. Anyone out there have this problem or have a idea what i can try next Link to comment Share on other sites More sharing options...
58Tucker Posted March 25, 2022 Share Posted March 25, 2022 (edited) I had a P0031 code and replaced the upstream O2 sensor with OEM Denso part. P0031 eliminated. Prior to that I had replaced the downstream O2 sensor and the catalytic converter. The catalytic converter code P0420 returned. I replaced spark plugs, PCV valve, used fuel system cleaner several times (in hopes that would clean fuel injectors), cleaned the MAF sensor, cleaned EGR valve, still unable to get rid of P0420 code. Cleaned the throttle body and idle re-learn, runs and idles better. DTC P0420 persists. Edited April 16, 2022 by 58Tucker Update / corrected with new information Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now