Engine Performance problem
2002 Saab 9-5 4 cyl Two Wheel Drive Manual 80,000 miles
I have an 02 Saab 9-5... And am experiencing misfiring when accelerating at fairly high rpms. The problem began during a coolant problem (bypass valve) when I was using water in the radiator for a couple days.
I just replaced the fuel filter, which I think made it marginally better, but the problem is still there. Any suggestions?
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)
Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include: Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires