Dreaded error code 26… need advice. (1 Viewer)

[drlaytn]

So… driving my 94 FJ80 home yesterday I noticed it idling lower than normal and feeling rough. It didn’t die. Ran fine under power.. seems smooth. Shortly. After I noticed the change, the CEL lit up. After I got home, I got out the trusty paper clip and the CEL blinked out a 26. So down the rabbit hole I went reading multiple posts regarding code 26. It seems like it could be a hundred different things. I looked for loose/cracked vacuum hoses… nothing. Checked the intake tube between the AF and throttle body… no cracks. Checked the main ground wire.. good. Pulled the plugs ( which only have about 1000 miles on them), inspected them… dry,clean, no buildup. Crawled under the rig and checked the O2 sensor plugs… dry and tight. Looked for exhaust leaks… nothing… I checked my snorkel for blockage… nothing… air filter is new and clean.
A little history on my rig… about 270000…the engine was totally rebuilt in June at Torfab… new Toyota short block remanufactured head, rebuilt injectors, removed egr,new exhaust manifold and new O2 sensors.
Given all that info… where else do I look? It seems that most postings point to the O2 sensors, but I can’t imagine 4 month old sensors going bad.
Any ideas on where to look next? It’s kind of maddening that code 26 leaves a lot to the imagination to try to figure out how the h*ll to fix it! Any advice appreciated. Thanks!

 

[voodu3]

I assume with egr delete you deleted the pair system and o2 sensors are on the exhaust manifold. You may want to check the wiring harness for the o2 sensors. I had one that got too close to the downpipe and it melted the wiring.

 

[Malleus]

It's not 100 different things. The horror stories you're reading about are written by people who haven't taken the time to properly diagnose the problem and troubleshoot the solution. Quit reading posts about other people's problems, open the manual and a beer. Once you've exhausted the Toyota documented steps to solve the problem, THEN go searching for other ideas.

Note that a proper diagnosis requires you to test in Test Mode, as well as Normal Mode. Test Mode exists for a reason.

 

[drlaytn]

The pair system is still there. Wires look good. Not sure why they didn’t remove the pair with the egr. I’m contemplating removing it and moving the O2’s to the exhaust manifold. I need to source the plates to cover the O2 ports on the exhaust. I’ll be sure to keep the wires clear of the exhaust. Thanks.

P.S… is there a downside to removing the pair? Emissions tests not required here. Wondering how it affects performance?

 

[CharlieS]

Agree 100% with Malleus. Do the tests. You can't assume.

My code 26 was fixed with O2 sensor replacement.

O2 sensors can be DOA or fail quickly. We chased bad O2 sensors on my son's Disco and went through two DOA bosch sensors. The big difference there was we could use OBD2 software to watch the sensors not cycling properly. You'll need to use an oscilloscope to see the same on an OBD 1 land cruiser.

There's no downside to removing the pair system.

 

[Mark W]

Just as a data point. Or several perhaps. Over the years, I have seen code 26 many times on my rigs and customers rigs. My personal experience... and only my personal experience... so far every single one has been a bad O2 sensor. That does not mean that every time in any rig this will be the case, but with my personal experience this is where I always start when I see 26.

And with the quality I see in far too many replacement parts these days. I may not expect any new component to fail quickly, but I never never rule it out either.

Mark...

 

[baldilocks]

The pair system is still there. Wires look good. Not sure why they didn’t remove the pair with the egr. I’m contemplating removing it and moving the O2’s to the exhaust manifold. I need to source the plates to cover the O2 ports on the exhaust. I’ll be sure to keep the wires clear of the exhaust. Thanks.

P.S… is there a downside to removing the pair? Emissions tests not required here. Wondering how it affects performance?

When I moved the 02 sensors to the exhaust manifold of my 93 the engine ran better if anything. Having those sensor up higher out of harms way is a good thing. The wire harness for one of the O2 sensors is routed from above the starter and over top of the transmission so there could potentially be damaged wiring.

 

[mudplacement]

Had a 26 from a broken injector coming partially unclipped resulting in sporadic injection on a cyl and a miss.

Just another thing to check, its probably o2 though