Car - 1996 Ford Ranger - 4L V6, 4x4, Auto trans, 126K miles

Problem - Idles poorly. Seems to miss when idling. Gets better as it starts to warm up - but have had issues coming to a stop and notice the problem after driving. Car owner (not me) mentions that the problems seems to be worse in the summer months than the cooler winter months.

Codes -

1) P0153 - O2 sensor. Exhaust is new - skeptical on leaks (don't own truck looking to buy).

2) P0401 - EGR Flow Insufficient - Reading the website this problem could be caused by multiple issues. Any suggestions on exactly where to start or what to replace for above problem would be appreciated.

3) P1151 - Heated Exhasut Oxygen Sensor indicating lean at the end of a test trying to correct for an over-rich condition. Sounds like this problem could be due to one of the 2 error codes above. But also sounds like it could be a vacuum leak - possibly related to EGR?

In closing -

I would like to know what needs to be replaced/fixed to correct the problem listed above. I had diagnostics performed to help but with so many potential issues I am turning to the community for any advice. I came across one thread with a similar issue on a Ranger and the remedy to the problem was replacing the thermostat. With so many potential paths to follow I want to take the most direct/inexpensive to fix.

Thanks in advance for the help.

 

EDITED FOR CLARITY (PASTED MY THREAD FROM OTHER FORUM) - COULDN'T MODIFY ORIGINAL POST


Car - 1996 Ford Ranger - 4L V6, 4x4, Auto trans, 126K miles

Problem - Idles poorly. Seems to miss when idling. Gets better as it starts to warm up - but have had issues coming to a stop and notice the problem after driving. Car owner (not me) mentions that the problems seems to be worse in the summer months than the cooler winter months.

Codes -

1) P0153 - O2 sensor. Exhaust is new - skeptical on leaks (don't own truck looking to buy).

2) P0401 - EGR Flow Insufficient - Reading the website this problem could be caused by multiple issues. Any suggestions on exactly where to start or what to replace for above problem would be appreciated.

3) P1151 - Heated Exhasut Oxygen Sensor indicating lean at the end of a test trying to correct for an over-rich condition. Sounds like this problem could be due to one of the 2 error codes above. But also sounds like it could be a vacuum - possibly related to EGR?

In closing -

I would like to know what needs to be replaced/fixed to correct the problem listed above. I had diagnostics performed to help but with so many potential issues I am turning to the community for any advice. I came across one thread with a similar issue on a Ranger and the remedy to the problem was replacing the thermostat. With so many potential paths to follow I want to take the most direct/inexpensive to fix.

Thanks in advance for the help.

 

Replace Oxygen sensor,

 

Is there a link listing all of the available trouble codes? I can see that I am starting from scratch with this Ranger. It may be a few weeks/months before I am in a position to offer pay back for the help that I will be getting here.

Also, I see that my signature has followed me from the PSD site to here. If I up date this site will It remove my signature from the PSD site?

Thanks,
Rog