2 failed air/fuel sensors

I have a 2007 Tacoma with the 4.0 with 196k miles. If it is saying both sensor 1 sensors have failed would you assume it is something else or could both sensors have failed. Bought truck with check engine light on so really don’t know how long this problem has been going on. I do know the fuel mileage is around 13-14 so there is something going on with fuel air mix. Thanks for the help and suggestions.

 

Check codes, o2 readings, fuel trims, do some actual diagnostics. Torque for Android and there's something comparable for Apple, plus an ELM327 obdii adapter.

 

I have a craftsman obd2 reader. It was throwing codes for bank one sensor 1 and bank 2 sensor 1. I’ve never used a scanner to read them other things you are speaking of but I will see what I can do.

 

It's just odd that both sensors would go bad at the same time. Most common check for one sensor bad is swapping sides of engine. I would doubt the sensors are bad and our trucks are known for easily clogged fuel pumps so those diagnostic items I listed would narrow in on fuel pump or other sources.

 

Are they OEM/DENSO?

 

http://densoautoparts.com/find-my-part

 

Bought with a 197k, and 10 years old.

AFR sensors are both throwing codes for mixtures being off.

Check all of the vacuum hoses, and intake couplings. Probably will find some leaks.

 

Also would show on fuel trims, if his craftsman reader shows that. The computer would be compensating with... More fuel for Un-metered air?

 

The fuel trims would be a good indicator. Some spray around all seals and vacuum hoses would as well.

 

What am I looking for in fuel trims?

 

You actual need to look at live data, short term fuel trim and long term fuel trim. Anything outside of 10%(POS or NEG) will set a code.