zzbear

Throwing codes P0134 (o2 no activity) and P0031 (o2 heater control). They started the day after I had an instant oil change. The workers were acting like something was wrong, but I didn't think anything of it then. Could they have damaged the o2 sensor or wiring trying to take the oil pan nut off? In any case, my instinct would be to replace the o2 sensor of course, but was wondering if that combination of codes means anything specific...

SatsumaxA

get under there and see if they just unplugged the wire from the O2 sensor. May have broken it off by accident but it is not any where near the drain plug, and the filter is on the front of engine. Good luck and let us know how it turns out.

zzbear

got under the car and all is intact. Wires look fine. One of the codes concerns the heater - not sure what that means... I checked all fuses re. the heater, but don't know how to check the relay. I use the torque ap on my phone, and it shows activity coming from both O2 sensors...

zzbear

O2 1 seems to stay pretty steady at .1 and O2 2 stays at 0 on idle and jumps to around .7 after accelerating.

jct

how many miles on your car... you might have to replace your sensors

zzbear

117k. Bought it with 99k in October. Do you recommend doing both? If not, which one is #1, the front one (the engine side of the cat) or the back one? I'm assuming #1 is the front one.

SatsumaxA

I think the #2 O2 sensor has the heated core in it as a control during warm up so the cars computer can gauge the A/F mixture burn exhaust before and after the catalytic converter during engine warm up. Do you have a header installed or cat-back exhaust installed? These sometimes throw codes, but usually right after install..
Suggest you change the #2 O2 sensor that is after the catalytic converter as you surmized already!! Good luck tho.

zzbear

Traced the connector back to under the center console next to the gearshift - got that off and ready to repair but can't get the darn o2 sensor loose. It's really frozen on the pipe. Giving up for today - don't have another day off until Tuesday. Thinking of getting my summer tires on and having them loosen it while it's on the hoist.

SatsumaxA

Shop should have no problem when you drive there with exhaust pipes hot..the hot exhaust will expand O2 mount hole and the threads won't be seized up so bad.