lean bank 1 / lean bank 2
I have a 2001 4.0 with a check engine light coming on once or twice a week, The codes are always lean bank 1 /lean bank 2. It seems like this happens when I let off the throttle.. and most of the time going down hill. I erase the codes and do not see anything for a few days. The only mod to the truck is an AirHog air filter. The truck has about 85,000 miles on it. Has anyone else had this occur? Any advice as to where to start is appreciated.