on my 1990 4runner 22RE with 260k mi. I keep getting 25 and 26 CEL codes. The truck seems to run fine. I replaced the AFM and o2 sensor. Couldn't find any manifold leaks. If I reset the ECU the CEL will stay off for a day or so, then will come on again. I am really tired of wasting time and money on this. I'm about ready to just unplug the CEL light

code 25 - lean
code 26 - rich

where shoud I start next? I was guessing maybe a fuel pressure problem? I don't have a gauge, so I'll have to go make one to test it out, if I should bother?

TPS? it seems to run just fine, so I don't see why this would be an issue?


cap/rotor/plugs/wires? I replaced them about two years ago, I don't think this would be a problem?

please help. I've searched and basically haven't found a single post that has a solution. they all just kind of dead end

 

Take a look at the service manual and see what Code 25/26 have in common.
Troubleshooting is a methodical analysis of a complex system.
There's a short list of things to check related to these codes. Check them one by one, don't go just swapping parts. You'll waste more time and money that way. EGR isn't part of those codes.
You can find a fuel pressure gauge at almost any auto parts store.

 

http://forum.ih8mud.com/79-95-toyota...on-tips-3.html
might be a little differant as this post had the 3.0, but gives you some ideas.

 

Hey, did you ever figure out the problem?

I have the same issue and runs fine now for like 40,000 and could never figure it out I've messed with the TSP a few times with no luck. Was thinking about replacing the fuel pump sine I put a new rebuilt in at 260,000 and now I am at 326,200. I'm guessing it's original and hope that may help...

If anyone else has been successful or care to share any words of wisdom, that would be greatly appreciated.

 

The "same" issue? Both codes? I could imagine a few cases where a weak pump might lead to a code 25, but not 26.

A fuel pressure gauge will tell you; much cheaper, and much easier, than replacing a fuel pump on a WAG.

After that, I'd look at the O2 sensor circuit.