A little background first, 2003 Ranger, 4.0, 203k miles. Check engine light just came on, no performance change, fuel tank cap was tight. I was wondering if there is a way to check the codes by cycling the key on and off. I know that with some older vehicles you could cycle the ignition in a certain pattern and it would make the CEL blink some of the codes. If not I have a friend with a code reader.

 

Try it, I forget if newer ones do that, my 85 bronk did. If your friend is busy, any parts store should be able to read it also.

http://www.ultra-gauge.com/ultragauge/index.htm also works well and numerous members have it. Including myself.

 

Do you remember the sequence? I think it was on off on off on off on but I'm not sure.

 

On and off 3 times. Third time it stays on I believe.

 

Awesome, thanks! Will report back.

 

3 cycles on and off, no-go, 4 cycles, no-go. Guess it doesn't work on OBD-II vehicles.

 

Ok, used my friends code reader and got a P0171 code. It was the only code so I cleared it. From what I understand a dirty MAF, vacuum leak, bad O2 sensor(s), dirty fuel filter, and even possibly EGR issues could cause this code. What about a bad coil pack? My friend has this neat little pen like device that senses electric current without punching through the insulation. He checked my plug wires and got lights blinking, showing current (spark) passing through all 3 plug wires on bank 2 (drivers side) and hardly any current on bank 1, again, all 3 plug wires. It would seem to me that no spark in bank 1 would cause a rich condition in bank 1, not a lean condition. Is the PCM trying to compensate for the lean condition by weakening the spark in bank 1 to make it run richer? After I cleared the code is when we noticed that bank 1 was getting little spark, CEL stayed off till I got out of the parking lot and was on my way home, then it came back on. Any ideas? I'm gonna check for EGR and vacuum leaks, also might try cleaning the MAF before I start throwing money at O2 sensors and a coil pack.

 

Any update Shaun? I'm chasing a similar problem.

Chuck

 

Chuck, turned out to be a vacuum leak. The silicone elbow that connects the EGR tube to the intake plenum had a 1/2" crack in it. Apparently it's a very common issue, you can only get the part from Ford and you have to buy the entire EGR tube with both elbows as an assembly. I think it was around $37 for it. The guy behind the parts counter even told me that a lot of the automotive shops around here that replace this part will buy the entire assembly, charge the customer for the entire part, then only replace the cracked elbow. If that's the case, what a bunch of crooks. Why not replace the whole EGR tube? I did it in about 5 minutes while I was at my Son's football practice. Took no time at all. I also discovered that the lower thermostat housing was leaking at the seam. Again, a Ford only part with a price tag in the mid $50 range. That one was a little more complicated but I managed to do it without removing the intake manifold. Just make sure you don't lose the 2 small clips that hold the 2 coolant sensors into the thermostat housing, not available from Ford but if you have a local wrecking yard with Rangers and I believe Focus' have the same clips.