Gunnut Posted July 22, 2006 Share Posted July 22, 2006 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? Quote Link to comment Share on other sites More sharing options...
93ls400walt Posted July 22, 2006 Share Posted July 22, 2006 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 Quote Link to comment Share on other sites More sharing options...
Gunnut Posted July 23, 2006 Author Share Posted July 23, 2006 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? Quote Link to comment Share on other sites More sharing options...
SKperformance Posted July 24, 2006 Share Posted July 24, 2006 What type of road and driving conditions is it when it happens? Quote Link to comment Share on other sites More sharing options...
Gunnut Posted July 24, 2006 Author Share Posted July 24, 2006 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. Quote Link to comment Share on other sites More sharing options...
93ls400walt Posted July 25, 2006 Share Posted July 25, 2006 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. Quote Link to comment Share on other sites More sharing options...
LScott400 Posted November 24, 2006 Share Posted November 24, 2006 Jim, Did you track down the culprit on this code? Quote Link to comment Share on other sites More sharing options...
Gunnut Posted November 25, 2006 Author Share Posted November 25, 2006 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. Quote Link to comment Share on other sites More sharing options...
UCF3 Posted November 25, 2006 Share Posted November 25, 2006 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. Quote Link to comment Share on other sites More sharing options...
Gunnut Posted November 27, 2006 Author Share Posted November 27, 2006 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 Quote Link to comment Share on other sites More sharing options...
LScott400 Posted December 2, 2006 Share Posted December 2, 2006 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. Quote Link to comment Share on other sites More sharing options...
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