I just bought an '02 ES300 with 163K on it. Runs great. But this morning it threw a code, actually two: 2238 and 2241. That is Bank 1 and Bank 2, sensor 1.

So, in reviewing prior posts, it looks it is the upstream O2 sensor that is often the culprit. I'm thinking that something different might be at play here since both came on at the same time.

So, I need some ideas, thoughts, of how to chase this down.

 

While it is possible that something common between the two failures, it is also a possibility that both are actually bad. I'll do some research and see what I can come up with... about the only two things they share are power supply and ECM... the codes are for failures in the hardware, not that they are reading improperly, so, usually the issue would lie within fuse, relay, wiring, ECM, or the sensor itself... without looking at wiring diagrams, I can probably tell you other things would share the fuse and relay, it is usually piggybacked on the EFI relay, but perhaps not...

 

What about the MAF sensor? I saw some folks saying that this cleared the code. However, in that case, they were getting one code or the other, not both.

 

I suppose it is possible, but from the text I am reading, it shows that those codes are set by a hardware failure of the air/fuel/o2 sensor or related power wire/controller, not by a false reading in one...

 

So, I went ahead and checked the air filter to make sure there was no major obstruction - there wasn't.

I pulled out the MAF sensor and shot it with some cleaner.

Cleared the code with my code reader. Drove a couple of errands since then and light hasn't come back on. Let's see how long it stays that way.

 

Every one of the confirmed fixes for either of these independently always results in an Afr/o2 sensor replacement... a loose wire, including ground could cause this, even if it is part of the heating circuit...

 

I started my car today and check engine light came on. same two codes. I have read the thread, did anyone find the best solution? Were is the location of fuses and relay to check first.

 

Tried to PM you doesn't work april of 2002 I believe toyota corrected the engine sludge problem