JasonPAtkins
Member
- Joined
- October 25, 2013
- Messages
- 11
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- Year, Model & Trim Level
- 2002 Mountaineer V8 AWD
My 140,000 mile late-'02 Mountaineer has had engine codes since I bought it. I'm trying to chase them down.
History:
I recently replaced a vacuum line that had a big tear in the elbow, using advice and pics from a forum post here (can't seem to find it now). That fixed one of the codes, maybe P0172 or something like that. I now have the above listed codes along with misfires on #1 , #4 , and misfires in the first 1000 revolutions.
At the time I did that, I also looked at the MAF, and it's totally clean inside the air intake tube.
Symptoms:
Other than the CEL codes, the motor has very little power for about the first minute or two you're driving. Then, all of a sudden (I assume after the computer has given up on whatever it was attempting to do and goes into failsafe), it will surge forward and be fine until the next time you drive it. Mileage isn't great, about 16 hwy.
Extenuating circumstances:
I live overseas, and last time I was gone, the Mounty sat for 2 years with a dead transmission. During that time, mice got into it and (along with making it smell terrible) chewed some wires, but only ones in the cabin afaik.
Diagnosis:
I believe I changed the plugs at around 120k. However, it seems possible to me that running with the cracked vacuum line for 10,000 miles could've fouled this set of plugs. So I'm going to replace them all, and hope that takes care of the #1 and #4 misfires.
However, it doesn't seem like bad plugs could be the cause of these O2 reading errors. I could actually have bad O2 sensors, but given that two of them are being indicated, it seems more likely that they're reading correctly and the O2 level really is out of range.
Where else should I be looking? Could this be consistent with a stuck EGR valve or something like that? Perhaps there are other places that this engine tends to leak vacuum that I should be investigating?
Any help would be appreciated. I'm getting sick of playing with it and wish it would just work, lol.
History:
I recently replaced a vacuum line that had a big tear in the elbow, using advice and pics from a forum post here (can't seem to find it now). That fixed one of the codes, maybe P0172 or something like that. I now have the above listed codes along with misfires on #1 , #4 , and misfires in the first 1000 revolutions.
At the time I did that, I also looked at the MAF, and it's totally clean inside the air intake tube.
Symptoms:
Other than the CEL codes, the motor has very little power for about the first minute or two you're driving. Then, all of a sudden (I assume after the computer has given up on whatever it was attempting to do and goes into failsafe), it will surge forward and be fine until the next time you drive it. Mileage isn't great, about 16 hwy.
Extenuating circumstances:
I live overseas, and last time I was gone, the Mounty sat for 2 years with a dead transmission. During that time, mice got into it and (along with making it smell terrible) chewed some wires, but only ones in the cabin afaik.
Diagnosis:
I believe I changed the plugs at around 120k. However, it seems possible to me that running with the cracked vacuum line for 10,000 miles could've fouled this set of plugs. So I'm going to replace them all, and hope that takes care of the #1 and #4 misfires.
However, it doesn't seem like bad plugs could be the cause of these O2 reading errors. I could actually have bad O2 sensors, but given that two of them are being indicated, it seems more likely that they're reading correctly and the O2 level really is out of range.
Where else should I be looking? Could this be consistent with a stuck EGR valve or something like that? Perhaps there are other places that this engine tends to leak vacuum that I should be investigating?
Any help would be appreciated. I'm getting sick of playing with it and wish it would just work, lol.
