Just the other night some punks tried to steal my catalytic converter from my 98 4runner but my alarm went off and scarred them away just in time because they had cut both sides all the way and the catalytic converter was hanging just by the rubber hanger. I drove the 4runner in the garage without the cat on and I welded it all back together and took it for a test drive and my check engine light went on and I pulled a P0125 and P0135 code, Was i supposed to remove the o2 sensors before welding? I never had an issue with the engine light until it was tampered with. Any help on this would be great.


Thank you.

 

I'd just reset the computer by pulling the EFI fuse or pull the negative battery terminal off the car for a few minutes. OBD2 won't turn itself off until a few driving cycles, if at all.

The O2 sensor is supposed to get hot, I doubt welding near it would have caused any problems.

 

I did reset the codes and they came back on as soon as i got on the freeway. I checked the sensor harness and noticed that two out of the four wires were cut and are too short to repair. I tried to call around and find a used one just for the harness but no luck yet. I might have to get a new one and i don't know if the Bosch brand is OK to use. I read another post on here that the Denso was the one to buy. Thanks again.

 

Were the cuts on the sensor side harness, or vehicle side? If it's sensor side, then yeah, just replace the sensor (go for Denso, not bosch. Check amazon, they are always the cheapest)

If it's vehicle side, than you can just solder in some new lengths of wire. Just be sure to use heat shrink to close it up and protect it. It will work better than electrical tape.

 

Sounds like the cuts are sensor side but close to the plug not the sensor. If so, you might try using those blue splice-in clips to go around the plug on those two wires. Solder the sensor end as Nelson describes with a few inches of 14ga. Then use the clips on the other side of the plug and wrap with tape. If it doesn't work, you haven't damaged anything, just pull the clip and tape the tiny slice in the insulation.

Otherwise, I agree, stick to Denso on a new one. Amazon has good prices. Use the Toyota part number and go here to get the Denso number. Don't use the vehicle look up because I think they have it wrong for your truck. But the interchange for the Toyota number gets it right.

 

Thanks for your help guys, I went to the junk yard and found a sensor for $25 and just used the male end of the plug on my old sensor. The check engine light has not come on so far.