CEL on stock 3.3L w/70k miles

[youngblood]

Haven't been a very active Solaraguy for the last few months, but I hope I can still tap the knowledge tree here every once in a while......

My '04 SLE V6 just tuned on the engine light when it was around 20 deg F outside (morning, first drive). The car is bone stock and I'm the only one that drives it. There are few if any indications other than the CEL that something is amiss.

I drove up to AutoZone and had the codes read and they are as follows:

P2238
"Oxygen sensor or A/F ratio sensor circuit low- bank 1 sensor 1"

and

P0031
"Oxygen sensor heater control circuit low- bank 1 sensor 1"

The printout lists some probable causes which include oxygen sensor failure, dirty or open connections in the circuit, etc.

Anyone have any success interpreting these codes on their 3mz?
I really don't have a mechanic that I have any faith in right now, so I may be attemping the repair myself. Any additional info that can be provided is greatly appreciated.

Thank you in advance!

[GzNutz]

Just reset the code and see if it pops up again. I throw that on occasion but haven't had any problems. If it pops up again after clearing, then seek help. Anything else funky going on besides the cel?

[youngblood]

Nah, not really. It seems be shifting a little funky between the middle gears (auto) and MAYBE not idling as smooth, but I may be imagining that. I do plan to pop the battery cable off. See how long it takes to set the code again.

[youngblood]

Turns out the sensor was in fact bad. Tested the heater circuit with a DVOM and it was out of range. I then simply replaced the sensor and reset the light.

This sensor (back side of engine on the exhaust manifold) WAS a little tricky to get to but its totally do-able. I put the car on ramps, found a good place to put my work light (its dark back there), and hit it with some penetrating oil. I used a sensor socket and a one inch wrench to break it loose. Even after 6 years in the rust belt, the sensor came right out! The pigtail connector was almost harder to get undone than the business end of the sensor! Its way up in there, but rest assured, if you need to do this job you can.

Toyota replacement parts ftw! Btw- Reggie is the man!