the truck was running very rough. found codes po171 and p2195 for o2 sensor stuck lean and bank 1 lean. replaced b1s1 o2 sensor also mass air sensor. this truck has only 33,500 miles driven. also had to reline front disc brakes ,replace front brake rotors and reline rear brakes and replace brake drums. this truck is not driven hard. seems like alot of problems for only 33,500 miles. *utr