Engine Performance problem
2002 Jeep Liberty 4 cyl Two Wheel Drive Manual 65,000 miles
My Jeep Liberty sport runs pretty good. Only at times does it hesitate and backfire from inside the engine compartment on the passenger side. For instance, i'll be traveling in 3rd gear (manual) at 35-40 and switch to 5th and it hesitates and backfires. I changed the plugs and everything was fine for about 2 months when it started doing this. When i'm in neutral and tap the accelerator pedal and rev engine, I hear what sounds like engine sucking a bunch of air. Could it be a intake manifold gasket?
Inspect and test all the following listed below: Oxygen sensor.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Manifold absolute pressure sensor.
Fuel pressure regulator leaking or defective fuel pump.
False air leakage.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.