2004 Pontiac Grand Am #2 Cylinder Misfire

LLOFTON

MEMBER
2004 PONTIAC GRAND AM

Engine Performance problem
2004 Pontiac Grand Am 6 cyl Automatic 158000 miles

My car hardly has any power. Sometimes when I take off (say from a light) the rpm's will go up to 3 or 4 just to get to 30 mph and the gears will only shift if I get off of the gas pedal (had transmission checked. It was fine). The car strains terribly trying pull a hill (small or steep). Sometimes if I press the pedal to the floor, the engine rev's but, the car doesn't really speed up like it should. I had the catalytic converter checked, it was fine. That's when I found out I had a #2 cylinder misfire. Machine has also read that I have emissions problems. I have replaced the EGR valve. Didn't work. I recently started hearing a very loud ticking noise. Don't know if they are related are not. Please help. Any information will be greatly appreciated.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Misfire at no.2 check rthe sparkplug, compression and injector for that cylinder

Lacking acceleration check the throttle position and manifold absolute pressure sensors to include a fuel pressure check

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