Code 25 & 26 (1 Viewer)

[landtoy80]

The wife had the 80 and after a hour and a half of driving the CE llight came on.
It was on for a while then turned off.
I checked it and its Code 25 and 26. Its lean and rich.
I cleared it and I have no CE light. Why would the light turn off? I thought when the light comes on it stays on?????

How can it be lean and rich at the same time? Bad gas???

 

[Russ in California]

I don't have the FSM in front of me, but I think these are the same codes I had on my 91. Follow the flow chart diagnostic and came up with O2 sensors. What a pain.
After swaping out the sensors I still get a CE light sometimes but it goes out. My mechanic thinks it's a bad ground to the exhaust.
JMTC FWIW,
Russ

 

[jjbodean1970]

just put a piece of black electrical tape over your check engine light, it won't come on any more!

 

[archie]

I got a 3fe and changed mine at 198k. No check engine light since.

 

[archie]

I meant I changed the O2 sensors.

 

[landtoy80]

Code 25 and 26 ,one is running rich air fuel mixture and the other is running lean air fuel mixture.
How can it run rich and lean at the same time???
I have new OEM O2 sensors.

 

[archie]

how long have you had them on? maybe they got disconnected? I had the same codes also and my light went on when I was going over 55 mph. My O2 sensors were original before I changed them.

 

[landtoy80]

I replaced the O2 early this summer. The light came on for a short while then turnd off.
Its off now and hasen't come on again.
It was a very warm and humid wet day.

 

[semlin]

Kurt, Rogue had the same code 25/26 problem a couple of months back. He did not post to say how it turned out but perhaps someone (maybe Rogue's parts pusher ) knows how he fixed it or whether the lighter fluid solution was employed.

https://forum.ih8mud.com/showthread.php?t=21614

I also hate to mention that it sounds like something the EGR system could contribute to. maybe check all those vacuum hoses are tight and connected up the right way!

 

[landtoy80]

I saw that post when searching (yes I search too ).
I hope it was a fluke. Unless the light comes on again I will leave it at that.