Check Engine REFUSES to go out

Purchased a salvaged title 07 Tacoma Sport for my daughter three years ago.

Wrecked front passenger side. Repairs were made, paint matched, less than 25k on it when purchased. Runs great, looks even better, it is a NICE truck! EXCEPT....the dang check engine light! The guy we bought it from said he/mechanics could never figure it out. We have replaced EVERYTHING the codes shoot out. The light used to stay off for a few weeks once codes were read and reset. Now it never goes out but there are no other issues. It runs fine.

Just this morning, I noticed the short pin fuse is "burnt". Switched it out for one in my wife's Tacoma and now the check engine light is off but the air bag, ABS, & brake light indicator are on.

I consider myself a pretty handy guy but this damn thing has got me totally stumped! I'm hoping someone out there can make me feel like a total dummie by telling me what the heck the issue is. I've spent quite a bit of money to no avail. It's time for her to get safety and emissions and it will not pass. Resetting no longer works.

Would appreciate ANY and all suggestions!

 

What code is coming up?

 

P0051, P0031- all sensors have been replaced. I'm confident that is not the issue. Shortly after the sensors were replaced, the check engine light would only be out for maybe 24 hours after being reset.

The short pin fuse was replaced this morning. The light went out, but then the radio didn't work, the airbag & ABS indicator lights came on. The short pin fuse was not making contact, it was not a tight fit at all and burnt. I tweeked it a little so now it is making contact and all the lights are out.

I'm thinking it's an electrical issue, it's the ONLY thing left?!

 

If you keep flagging O2 sensors, have you checked the catalytic converter? From the codes, it looks like something is going on in the exhaust system. An 07 shouldn't need new sensors unless the cats are running super hot or went under water.

 

The codes say the sensor heaters are not working (or the sensors have no heaters). What did you replace the sensors with, are they the required proper Toyota sensors or some ebay junk????

 

Take it to the dealer. Tell them you need a seasoned mechanic good with trouble shooting.

 

check the harness or any wires where the truck had repairs couldve damaged the harness