Hello, all. My 22RE is throwing a lean air/fuel ratio error (code 25) and I just had a few quick questions! It's worth noting that there were no symptoms prior to the error, in fact, she's running better than ever.

I recently adjusted the valve lash. Could this have anything to do with it? I'm fairly confident the vacuum lines are routed properly and sealed.

I also replaced the PCV valve with a used but working unit from a 22R. Maybe this is the source of some sort of vacuum issue? I might just go ahead and pick up a replacement from a local parts store.

Thanks for your input!

 

Will almost guarantee it's your O2 sensor.

Get a denso or OEM. Don't know if you have the heated sensor or not, but don't, whatever you do go and get a cheap universal sensor. You will think your O2 is fine since it's new, but still get the code, then chase other things. Save your self the headache and get the correct one. Seen too many make a mountain out of a mole hill on this issue...

 

So I decided to pick up a new PCV valve and reset the ECU to see if the fault would reappear. The CEL came on again today and turned off shortly after. I think I'll go ahead and replace the O2 sensor and see if that clears the light for good.

Thanks!