Hey y'all! So the code popped up about a month ago, I've cleaned the MAF sensor, checked for vacuum leaks, and changed the fuel filter out( nothing to do with code). The CEL has been cleared and has continued to come back on, so Ive narrowed it down to the O2 sensors. Well I went into AutoZone to get prices and one of the guys told me he had a '99 F150 with the same problem. He then told me before I replaced them to take them out and clean them with a wire brush. I just kinda looked at him, and he explained that sometimes the sensor itself isn't bad, it just has so much carbon build up that it can't process everything right. Which kinda makes sense. But the autozone round here, most of the guys would #?*! up a wet dream if ya let em. Just kinda curious if anybody's ever tried this or even heard of doing this before.

 

What's the description of that code?

 

Try testing the sensor first. Here's how : If you don't have access to live data from the PCM you can use a digital volt meter to determine if sensor works. Probe into the connector with a paper clip (not a coloured one). The signal wire is usually grey. The ground is usually black. The two white wires are for the sensor heater. Signal wire voltage should flctuate between 0.1V and 0.9V. Low voltage is lean, high voltage is rich. If voltage remains low, try introducing a rich condition to see if it changes. You can do this by pinching closed the fuel return hose. This increases fuel pressure and causes a rich condition. Sensor voltage should go to almost 1 volt (for a few seconds). If it does-the sensor is likely NOT your problem.If the sensor doesn't respond to this condition and remains low-It's likely faulty. Then you might want to remove it and try cleaning it.

Bottom line is..........If the o2 sensor is saying the exhaust is lean..........Maybe it is!!!!!!!