P1021 Mitsubishi Auto Trouble Code
P1021 Mitsubishi OBD2 may also be triggered by faults earlier down the line. For example, a dirty MAF sensor might be causing the car to overcompensate in its fuel-trim adjustments. As a result, oxygen sensors are likely to report fuel mixture problems.
Some problems such as misfires and evaporative emission (EVAP) leaks can be very challenging to nail down. Misfires can be caused by ignition problems, fuel problems or compression problems. The underlying cause might be fouled spark plugs, bad plug wires, a weak ignition coil, dirty injectors, a shorted or open injector, low fuel pressure, a vacuum leak, a leaky head gasket, burned exhaust valve or a camshaft with a bad lobe.
P1021 Mitsubishi Possible Solution:
The firing order is an important part of the overall design of the engine and is determined during the design of the engine to eliminate as much engine vibration as possible. If the firing order is changed or adjusted, the ignition from the spark plug is delivered at the wrong time and the engine functions poorly or does not run. The firing order for a particular engine is typically found in the repair manual specific to that model.