Slow Shifting, High RPM, & CEL
I'm new to the site and a new diesel owner. I appreciate all the valuable information I have read on this site and hope to continue learning from everyone here.
I have a 2003 F250 XLT 6.0 w/163,000 miles that I have been having a little trouble with lately. A week ago I replaced the oil cooler, deleted the EGR cooler, oil and filter change, internal and external transmission filters and transmission fluid change.
RPM raises to about 3500 before the gear shifts and the last time I was driving it the CEL came on. I took it to O'reilly's and they pulled DTC p0238. I have also noticed a significant loss of fuel mileage.
I apologize for the long thread and would appreciate any response that can help me with these issues.