Apparently, the adaptations don't reset just because a new part was installed, and the swings/corrections it reads after the part is installed (if it fixes something) simply tells the computer that another major shift occurred (because it had re-adapted to the new mixture needs) and trigger the CEL ...

FIXED !! (let's hope I didn't jynx it...) Ok, here's the deal. It's been over 5k miles since I installed the spacer and replaced the PCV Trap. (See my last post) I did both of these things together even though neither were "needed" as the last attempt to fix this problem, hoping (and not caring ...

I added the spacer, ran some Techron (two tanks @ recommended Oz/G) and replaced the PCV box because.. well why not at this point. Once I reset the code and the ECU, I went over 1,500 miles without the MIL. I have yet to go more than two tanks without the MIL in literally 4 years. However, after ...

Already been done, twice. It’s mentioned in the list.

Hi All,

Following back up on my original post that started this chain. After giving up, I went in for a Serpentine belt service and the technician noticed that 2 of the 4 studs holding the Cat to the Turbo were missing, and presumed that extra air was coming into the exhaust before the sensors and ...

Wow, that is crazy. Glad you got it fixed. Unfortunately for me, it was the Volvo dealership that installed so I would have to assume it was an OEM, but I guess I should still get under and verify.

Hi Everyone,

Just an update here - I am the guy that posted the original thread. I am still having the same problem (full list of replacements below). I have honestly given up, it just doesn't bother me anymore - maybe when I go to sell it I'll care again. I am taking my car in for a trans. flush ...

It has 113k miles, this issue actually started 85k! Its been almost 30k miles of diagnosing, fixing, and then the light returning a couple/few months later. I am the second owner, and purchased it with 68k miles on it (dealer inspected). Zero other issues with it. I live in Colorado, and encounter ...

Hi all,

I've been battling a P0420 code from the CEL light for a YEAR now. I have replaced the following things. The dealer and another certified Volvo mechanic have both worked on this car (literally everything else is perfect on this vehicle, and maintained religiously) and they have affirmed no ...