ctown2
Member
I have a '98 expedition with 144K miles. I need some help troubling shooting a random misfire in the #8 cylinder(s). About a month ago, I had the following CEL codes; #8 misfire, system to lean (bank 1&2). I changed out the plugs, wires, and coil packs, and reset the CEL. I never got any codes tell about a week ago. This time it was simply a #8 misfire. Changed the plugs and wires again, and tested the coils with my multimeter (showed the right resistance on both primary and secondary).
Now after reseting the CEL light again, my wife drove less than 50 miles and it came back on with the following. #8 & #1 Misfire, system to lean (bank 1 & 2), and EGR valve. I have not had the chance to pressure test the cylinders to isolate the problem, but that is next on my list of things to do.
Here's my question, are the misfires happening as a result of EGR? I noticed that it idles rough under 1000 rpms, but over 2000 rpms it seems to smooth out.
Here's the actual code numbers that keep popping up;
308 (Misfire on #8)
401 (Exhaust Gas)
301 (Misfire on #1)
171 (System to Lean Bank 1)
174 (System to Lean Bank 2)
I've replaced the following; plugs, wires, coils (under 1000 miles on the coil packs), EGR valve pressure sensor, EGR control solenoid. I bench tested the EGR and it holds a vacuum with compressed air ran through it.
Any idea what I'm missing? Or next steps to take?
Craig
Now after reseting the CEL light again, my wife drove less than 50 miles and it came back on with the following. #8 & #1 Misfire, system to lean (bank 1 & 2), and EGR valve. I have not had the chance to pressure test the cylinders to isolate the problem, but that is next on my list of things to do.
Here's my question, are the misfires happening as a result of EGR? I noticed that it idles rough under 1000 rpms, but over 2000 rpms it seems to smooth out.
Here's the actual code numbers that keep popping up;
308 (Misfire on #8)
401 (Exhaust Gas)
301 (Misfire on #1)
171 (System to Lean Bank 1)
174 (System to Lean Bank 2)
I've replaced the following; plugs, wires, coils (under 1000 miles on the coil packs), EGR valve pressure sensor, EGR control solenoid. I bench tested the EGR and it holds a vacuum with compressed air ran through it.
Any idea what I'm missing? Or next steps to take?
Craig
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