I was only going 15 mph. Shifting seemed not good. Added 5 gallons premium fuel. Ran better. Speedometer acted normal. rpm jumped at times. light still on. running rough. made it home. Where do I start to fix this?
83,000 miles. The service light came on tonight. The speedometer showed 90 mph on 2000 Lincoln Navigator
have it scan tested for codes and go from there
start by pulling code(s)