Must be Christmas because my dash just lit up like a tree!

[Mikes-13]

2002 Check Engine Light, VSC Off & VSC TRAC lights
pulled code P0420

Just driving and switched out of 4Hi back to 2wd when the lights came on. No noticeable change in motor.

just started to search forum

 

[3gsdad]

Check over in the 4th gens. The later 3rd gens shared some of the VSC/ATRAC stuff with the 4th gens.

I have a 4th gen that did that. It had something to due with emissions. It was a while ago so I can't remember exactly what it was. Also make sure you gas cap is tight

 

[fblainen11]

I have that occasionally when I lock the center. I just clear it and go about my day. No issues. Yesterday I drove around quite a bit with center locked and have had no lights.

 

[StreetCreeper]

Am I missing something or this probably just a bad o2 sensor?

 

[TheDurk]

That is, in fact, the '01-'02 "Christmas Tree." It happens all year long. It's nothing more or less than a normal CEL on the other years. Some dippo engineer decided people were ignoring the normal CEL and tied everything else in. (Forgot that in my recent list of why I would not want an '01-'02.)

Treat it as as normal P0420. Check first for any exhaust leaks or damage to your cats. Then, change your rear O2 sensor if it has 75k or more on it.

One GOOD thing about '01-'02 is you can try the anti-fouler trick if that doesn't work. Google it.

 

[offroadxplr]

Yep. Normal when the check engine light pops. I've also got an '02, and it throws a P0420 about once a month.

Sometimes, I leave my CEL on, since I haven't done the VSC/TRAC disable mod. Makes for much better snow driving.

 

[Mikes-13]

Reset the Code

I reset the code and it hasn't come back on yet so far.
Both sensors are new
Muffler is new but aftermarket
recently tuned

I really want to replace this flow master muffler with a quiet OEM

 

[gtxtom]

Just had the same lights/CEL come on last week. Installed a Denso rear O2 sensor on Saturday.