Desperately in need of advice guys. This has been an ongoing issue for years and it seems to be getting worse. My big '97 Sport pops the P0125 code. It started this about 5-6 years ago. Back then it'd happen once or twice a year and seemed to be strictly related to how well the coolant system was bled. Now it happens up to 2 times a day.

The dealership is stumped. Four different techs have worked on this over the years as well as myself. We've been through the entire list on Mitsu's troubleshooting database several times including replacing the ECU. ECT, O2 sensors, etc. have been replaced multiple times.

It is NOT engine related as this problem reared it's ugly head years before I replaced the 3.0L with the 3.5L last spring. The engine replacement had no effect at all on frequency or the conditions under when it triggers.

I've ruled out exhaust leaks or anything related - again - as I've replaced the exhaust three times since '98 and there's never been a change.

Both O2 sensors have been replaced a dozen times. I've used the dealership sensors, Nippon and Bosch. No change.

The problem is MUCH worse when as the ambient temperature goes up. In the winter it hardly does it at all - if at all. Now that it's spring and the temps are back in the 60-70s its back up to once every couple days or once/twice a day.

We just went through the top end looking for vacuum leaks last week and found nothing.

No other codes trigger - ever. Gas mileage is back up to 17.5 average and there's no driveability issues. Mileage is a tad on the low side for DD usage, but not abnormally so given how crappy traffic has been, the wind and adding 8 miles of steep up hill drive to my new place.

This is a real PITA as I've got an emissions test coming up in June and any trouble codes - pending or otherwise - are an automatic failure.

Need suggestions guys. Everyone here is flat out of ideas. <img src="/forums/images/graemlins/frown.gif" alt="" />

Edward
www.4x4extremesports.com