thoughts on Lexus RX with P1155

[mendozer]

My buddy's Lexus (RX?, the Rav4 clone) has a P1155 code I diagnosed for him. After clearing it came back the very next day, making me think it's something imminently wrong as if it was a random code, then it would take some time to come back.
First thought was just replace the air/fuel sensor, but then I thought of the things that lead to that sensor...
air filter, MAF sensor, throttle position sensor, fuel injectors.

What's the likelihood those things are needing to be fixed verses the sensor itself? Those sensors are supposed to last a while aren't they? His is a 03, no idea if it's the original sensor, he's only owned it for 4 years.

 

[Dillusion]

If its an 03 its been 17 years. Not sure if you meant 13.

If you have a OBDII tool than can show voltages of the O2 you can look at it that way. I believe it should go between .1V and .9V. If not responding probably a bad O2. But while you under there make sure the wires not damaged either.

If you don't have a tool you can read the resistance of the sensor.

I would honestly forget about the other stuff you listed for now the code is pretty much telling you where the problem is.

 

[mendozer]

It's an 02 I was wrong. I meant he owned it for only 4 years.

He needed to rush to emissions on the 31st before the state shut down their emissions stations so he rushed to Vatozone to get a sensor and wrenched on it to get it in there.

He didn't get it done in time so he logs on this morning only to find out he could just renew it haha. Emissions wasn't needed after all. He texted me today that the code came back, so we're gonna scan it.
And the OBD I have just does codes. It's a bluetooth unit. I use the Torque app with it.