2005 Pontiac Sunfire Engine is missing and the RPM

2005 PONTIAC SUNFIRE
94,000 MILES • 4 CYL • 2WD • AUTOMATIC
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BUSYMOM42KIDS
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the engine light has stayed on. The engine acts like it is missing. It has problem reaching speed. The RPM want to rise, but it jumps down and loses power.It makes the engine to run rough. I have never replaced spark plugs and wires. It has 94000 miles. The fuel filter has been replaced. I have no ideal where the spark plugs are located. Please, advise me. A systems diagram of this car would be nice.
Please, list all possible problems.

Thanks
May 28, 2009 at 5:38 PM
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RASMATAZ
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You need to have the computer scanned for code/s this is your starting point due to the CEL being On.

Possible causes:

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
May 28, 2009 at 7:08 PM