I have a 1999 Chevy 3500. At some point, check engine light is on with a lean running code. Any idea what's caused this? I believe it's the fuel filter. It hesitates while on gas pedal too.
First thing you could do would be to change the fuel filter. I know why they run lean and there are 35 dozen reasons why a car can run lean. The main causes are: too much air, not enough fuel, or any combination of the two of those.
It can also be a bad MAF sensor; it can be a leak in head gasket; it can be a weak fuel pump; it can be weak fuel injectors; it can be air leaks on intake manifold. It can be air leaks on the fuel injection line. It can be all kinds of things.
You’ll want to pray that it is something simple like a bad fuel filter. If you do change a fuel filter, also have a fuel pump pressure replaced, because a weak fuel pump will do the same.
If you want to have this diagnosed, a certified technician from YourMechanic can come to your home or office to diagnose your Check Engine Light and make the proper repairs.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing