THE TRUCK IS RUNNING OK NOT MISSING AND NO LOSS OF POWER.
CHECK ENG LIGHT CAME ON,WENT TO AUTO ZONE AND CODES PO402 AND P0340 ARE ACTIVE. on 2000 Ford Ranger
Go to: engine codes.com
1 more answer
first off what are these codes. and sometimes momentary malfunctions will register a code. so find out what these are and please post them