speedometer
Posting Guru
Joined: Oct 2005
Posts: 2,209
Likes: 1
From: Louisville, Kentucky
Welcome to FTE mrplum! 
The speedometer is electronic and with that symptom, I would suspect it to be faulty. Before condemning it however I would unplug it from the truck and see if it remains stuck at 70 MPH.
No, you don't have bad O2 sensors with those DTCs. You have a vacuum leak. Check the air intake ductwork for leaks after the MAF sensor on to the throttle body. Good luck!
The speedometer is electronic and with that symptom, I would suspect it to be faulty. Before condemning it however I would unplug it from the truck and see if it remains stuck at 70 MPH. No, you don't have bad O2 sensors with those DTCs. You have a vacuum leak. Check the air intake ductwork for leaks after the MAF sensor on to the throttle body. Good luck!
