Scanner Showing Code 25

[Gunnut]

Got my fancy code reader the other day. (its basically a wire) I just pulled the stored code.

Code 25 Air–Fuel Ratio Lean Malfunction

This mean I'm running lean?

The CEL comes on in the morning on my way to work at about the same spot. It goes off a few miles later and then the next morning it come back on.

What should I be looking at?

I've been thinking of doing the TB cleaning. Is there something I can maintain on the AFM as well?

[93ls400walt]

Manual states that the main O2 sensors are being affected by the following:

1) open or short in main O2 sensor circuit.

2) Main O2 sensor

3) ignition system

4) engine coolant temp. sensor

5) blocked injector

6) volume air flow meter

7) loosr engine ground bolt

8) foreign object cought in valve

9) fuel line/injector leak or blocked

10) timing belt slipped

11) engine compression

12) ECM and or wire harness

[Gunnut]

Thanks for the info Walt.

Since the code is intermittent, is it possible to narrow the list down a bit?

Anybody have any experience withe their car throwing this code and what was the fix?

[SKperformance]

What type of road and driving conditions is it when it happens?

[Gunnut]

Smooth roads cruising anywhere between 35 and 45. Engine about 1/2 of normal operating (observed) temperature.

I used to have an old POS S10 pickup that the CEL light would come on but you could tell by the way it ran that it was on.

With the Lexus I notice no difference in performanance when it comes on or goes back off.

[93ls400walt]

I don't know about narrowing it down. But the list from the manual I assumed started with the most likely. Also if your car only does this around a certain temp. The O2 sensors are temp dependent for how they adhust. And the list did have the coolent temp sensor as an option.

[LScott400]

Jim,

Did you track down the culprit on this code?

[Gunnut]

I never did. I ran some injector cleaner through the tank and it went away on its own. I haven't seen the code in quite some time now.

[UCF3]

I never did. I ran some injector cleaner through the tank and it went away on its own. I haven't seen the code in quite some time now.

Pretty sure it will be back. You should consider replacing all four sensors. I did and haven't seen the code come up.

[Gunnut]

Wouldn't you know it? It re-appeared just last night. I knew I was going to jinx myself by responding the way I did.

JimA

[LScott400]

Sorry about that - didn't mean to put the whammy on ya

I has the same symptom for a few weeks and then it went to a constant CEL. Had a trip to make so I ran it down to 3/8 of a tank and put a can of Seafoam in. Ran it another 125 miles until the amber fuel light came on. Then put in a can of the higher dollar Berryman's and drove another 10 miles. CEL no longer illuminated. Guess I'll find out how long that lasts.