Engine Codes 25,26 Lean/rich Fuel Mixture

chris17house · July 31, 2005

Well I was in an accident and an old man with a truck slammed into the rear passenger side panel of my 1991 Lexus ES250, and about a week later my car started doing the folowing.

-I feel a substantial power loss, especially when I go up hills. The more gas throttle i give the car when going up hill, the slower it goes.

- The engine light has also came back on, and turns on and off at its own discretion.

When I,m in the garage and i rev up the car to about 4000rpm the car spools back down backfires.

I took the car to get a diagnostic reading and the Codes (25,26) came back which indicate a Lean/Rich fuel mixture. I was wondering if anyone else has had this happen to their car.

I would appreciate any help seeing as how im a college student with little cash.

Thank you in advance

Chris

Toysrme · July 31, 2005

Replace the o2 sensors. You can find generic replacements (you splice in, or splice the old o2 connector in) for like $25-$30 isntead of the $60-$90usd real replacements cost.

Since you got whacked in the !Removed!, lay under the back of the car and make sure the exhaust is OK.

chris17house · July 31, 2005

Hey thanks for the quick reply, Those are two things that the repair guys said are ok with the car. He said the exhaust is ok, as well as the 02 sensors.

Could it be spark plugs and wires?

Or should i just replace the 02 sensors anyways?

Thanks again

Chris

Toysrme · July 31, 2005

You need to understand. These things (OBD-I N/A Toyota computers) will not typically throw a rich/lean code. You can triple the amount of fuel you put in them, and they run so rich they billow black smoke anytime you're on the gas - no code will be stored, no CEL will come on.

The ECU's just really, really don't care! (A blessing for performance tuning, but it's no where near as good troubleshooting, or finding problems!)

If the o2 sensors are OK, you can pull the EFI fuse for a second & put it back in. That'll clear all the stored data.

No, probably not plugs & wires.

Look under the back of the car, and make sure the exhaust tip, muffler, and muffler pipe isn't banged up. Ya never know when a mechanic see free money.