Meadowlark Lemon
Member
- Joined
- October 10, 2019
- Messages
- 33
- Reaction score
- 12
- Location
- OH
- City, State
- Springboro
- Year, Model & Trim Level
- 1997 Mountaineer
Hi everyone,
Apologies in advance since I know this topic has been covered numerous times, but none of the other threads point me in quite the right direction.
Part of the problem is I am not sure if I have an early or late model 5.0, since they apparently changed the EGR system between 1996 and late 1997. I believe this dictates whether I have a DPFE or not.
Vehicle is a 1997 Mountaineer 5.0, AWD, tow package, 185,000 miles. Burns about 1 qt of oil per 1000 miles, averages about 15 MPG in mixed driving. EGR is located on the back of the upper intake elbow, almost under the cowl.
Symptoms are as follows:
Pretty consistent P0402 EGR excessive flow. Sometimes a P0153 - Heated O2 sensor1, bank 2 slow response. Even more rarely P0351 Ignition CoilA, primary/secondary - circuit malfunction. It is not present now and I don't remember exactly what it was.
Possibly unrelated, but I think the trans shifts a little later than it should (1-2 and 2-3) and an occasional surging feeling cruising at moderate speed (35-45 mph). That could just me being a little too picky.
Diagnosis steps so far:
I've removed the vacuum tube from the EGR valve and if I pull vacuum on the tube at idle, the engine will stall out, so the diaphragm appears to be good and the valve is not completely stuck.
I've driven with the EGR valve disconnected and I get only a P0401 - EGR insufficient flow.
This leads me to believe the EGR valve is not a the root of this issue, but some sensor that tells the ECU / PCM the valve position is out of range.
Any ideas?
Thanks,
Andrew
Apologies in advance since I know this topic has been covered numerous times, but none of the other threads point me in quite the right direction.
Part of the problem is I am not sure if I have an early or late model 5.0, since they apparently changed the EGR system between 1996 and late 1997. I believe this dictates whether I have a DPFE or not.
Vehicle is a 1997 Mountaineer 5.0, AWD, tow package, 185,000 miles. Burns about 1 qt of oil per 1000 miles, averages about 15 MPG in mixed driving. EGR is located on the back of the upper intake elbow, almost under the cowl.
Symptoms are as follows:
Pretty consistent P0402 EGR excessive flow. Sometimes a P0153 - Heated O2 sensor1, bank 2 slow response. Even more rarely P0351 Ignition CoilA, primary/secondary - circuit malfunction. It is not present now and I don't remember exactly what it was.
Possibly unrelated, but I think the trans shifts a little later than it should (1-2 and 2-3) and an occasional surging feeling cruising at moderate speed (35-45 mph). That could just me being a little too picky.
Diagnosis steps so far:
I've removed the vacuum tube from the EGR valve and if I pull vacuum on the tube at idle, the engine will stall out, so the diaphragm appears to be good and the valve is not completely stuck.
I've driven with the EGR valve disconnected and I get only a P0401 - EGR insufficient flow.
This leads me to believe the EGR valve is not a the root of this issue, but some sensor that tells the ECU / PCM the valve position is out of range.
Any ideas?
Thanks,
Andrew