My son is at college and has a 2 hour drive home. His check engine light is on and the truck will not register a reading on a diagnostic machine. He just replaced the fuel pump 2 weeks ago. The truck stalls and runs terrible. Could this be a spark plug issue; engine knock sensor or another sensor? What do we do if we can't get a code on a diagnostic machine? Should he drive the truck from school? Thank you! Engine dies and bogs down.
My car has 138000 miles.
My car has an automatic transmission.
If the engine stalls during travel, it can cause a hazard for other drivers on the road. If the vehicle does not run, your son should not drive it any extended period of time. The issue could very well be spark or fuel-related. Start by replacing the spark plugs. While doing this, check the spark plug wires. Make sure the cables and the boots (part that connects to the plug) are clean and in good condition.
When the fuel pump was replaced, did the fuel filter get replaced as well? The fuel filter can cause major flow restrictions and rob the engine of the fuel it needs. Many sensors can cause this issue. It would be expensive and time consuming to attempt to replace them one by one. However, your options are limited without the OBD-II connection. You may want to attempt to diagnose the issue with the OBD-II connection and make that repair as well. This can be complicated, and you may want to seek professional help for that repair. A certified technician from YourMechanic can inspect the stalling issue and advise on ways to repair and optimize the drive.