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My KOEO codes were fine, but my KOER codes were in this order. 41, 25. Can anyone asssit with these? First I thought they were supposed to be in asending order.
41 - (R) System lean - Fuel control. The O2 sensor is new. Why would it be running lean? The truck runs good, I was just curious what codes it might produce.
25 Knock sensor not tested (ignore if not pinging). I don't believe I have any knock issues.
the system could be running lean do to the tps (throttle position sensor) gone bad, try replaceing that... i had a similar problem the in the oppisite direction..mine was too rich.
Had you preheated the engine (and O2 sensor) prior to running KOER? The O2 sensor must be warmed up before it works. If the O2 sensor was cold, it sends a low voltage to the PCM, which is the equibalent of an engine indicating lean.
Then you need to look at other things that can effect the mixture. If you read the EEC-V article in a professional manual, among the first battery of tests for an O2 sensor code is to check the fuel pressure and fuel delivery.
Also don't forget to make sure the wiring is up to snuff. Didn't you mention elsewhere that the wiring was laying on the exhaust? It happens and that can cause problems for the PCm being able to read the O2 sensor.
Yes, the wires were on the exhaust, but I went to the bone yard and bought replacement connections. I soldered them in, disconected the battery and drove 10 miles and ran codes again, only to get the same results.