Michael Felt

Jack88

There half a dozen possibilities. Vacuum leak, clogged fuel filter, failing fuel pump, MAF sensor fault, throttle body fault, or any number of other things. This is far too general of a question, the specific code would help, as would how the car is running or other possible symptoms or related events.

mcs

Almost everything in the engine has it's own fault code - except bad fuel pressure.

The way the system works with the two fuel pumps is that when starting, they both work for 30 seconds then the secondary pump shuts off until high load or cross pumping situations need it to come back on.

If lean fuel codes are the only issues and the car refuses to run properly on the highway or stalls, but fires back up and runs for 30 seconds, then the main fuel pump is failing.

If you are stuck in a place with this issue, above the battery is the fuel pump relay. Remove the relay, hard wire the fuel pump and if it comes good, it will get you home easy and allow the car to work while you get another pump.

Jack88

That implies that it is definitely a fuel pump issue, but without more information as to what the car is doing, nothing is certain.