Must be black smoke? Indicating lean would mean pcm is dumping extra fuel to compensate, creating the black smoke. 300k is lot of miles, have you ever changed the o2 sensor? I never change unless the sensor can definitely be found to be bad. Look at the front of your engine right around the valve cover where it meets the cylinder head. Can you find a single wire, maybe orange in color? It will be bolted to the cylinder block by itself, this is a dedicated ground wire for the o2 sensor, lots of the time, especially with your mileage and age of car, this wire connection will become corroded, which will cause the circuit not to switch rich to lean, or vice versa, sometimes during a koer test, it will show correct, other times it will fault, it will act up on it's own with no regularity. See if you can find this wire, it's there somewhere, not too familiar with the escort motor. As far as maf, I would disconnect the sensor plug and clean it up, put a little dielectric grease on the connector, same with the tps connector, sometimes it will help. 300k is good miles, car has been good to you, just some things that won't cost an arm and a leg to start at. Never spend money just replacing parts as a shot in the dark, you only have to read any number of posts on here to see where all kinds of money is spent with no resolve of the issues.
Saturday, January 6th, 2007 AT 4:56 PM