P1391 Engine Trouble Code
When you check engine light came on code P1391 the reason should be Engine Light ON (or Service Engine Soon Warning Light). However your vehicle's manufacturer may have a different definition for the P1391 OBD-II Diagnostic Powertrain (P) Trouble Code. So you should chech it on our car models.
When the check engine light comes P1391 code on the first you should check is the gas cap. Pull over, retighten it, and take a look at the cap to see if it has any cracks in it. Continue driving and see if the check engine light turns off. Alternately, you can purchase a gas cap for about $3 at an auto parts store. All you need to do is take the old one off and screw on the new one. If you've already made it to the store, you might as well just replace it. While not car-threatening, it's good to take care of this right away to improve gas mileage.
P1391 Code Meaning :
|OBD-II Diagnostic Powertrain (P) Trouble Code For Engine||Fuel And Air Metering||Fuel Rail Pressure Sensor Circuit Malfunction||Cylinder 4 Contribution/Balance Fault||Glow Plug/Heater Circuit 'A' Malfunction|
The oxygen (02) sensors on your car measure the oxygen in the exhaust to determine how rich or lean the ratio of fuel and air are in the cylinders. Optimizing this mixture means better fuel economy and fewer exhaust emissions.
P1391 OBD-II Diagnostic Powertrain (P) Trouble Code DescriptionP1391 OBD-II Trouble Code Glow Plug Circuit Low Input Bank 1 is one of the definitions for the P1391; however your vehicles manufacturer may have a different definition for the P1391 code. Please check below for your specific P1391 code.
Reason For P1391 CodeThe reason of P1391 OBD-II Engine Trouble Code is Fuel Rail Pressure Sensor Circuit Malfunction.
P1391 the main thing to check is to verify the operation of the VCT solenoid. You're looking for a sticking or stuck VCt solenoid valve caused by contamination. Refer to vehicle specific repair manual to perform component tests for the VCT unit.