1994 pontiac grand am engine problem

I went in and changed the catalytic converter with no help also. To give a little more information. After the car had been sitting all day, it started with no hesitation. It still had a bad miss, but it started and moved under it's own power. I noticed after about 10 minutes once the motor had warmed up that the miss got really bad and the car eventually stalled. It would only restart if I held the gas pedal to the floor and the miss and backfiring was terrible. Could this be a bad O2 sensor or something else?

Have also replaced the 02 sensor and the ignition coils and cleaned the injectors with no help. Could this be a timning issue?

I am having an almost identical problem with my 99 4 cyl. grand am. It runs great for about 10 minutes, then crapola. Feel like it's running on 3 cylinders. Started as small hesitation at highway speeds under acceleration and got bad in about 3 weeks. Now always runs poorly. I replaced the fuel pressure regulator with no help for starters. Am still working at it and will let you know if I get mine fixed before you.

I have found that very often the coil housing is the most likely culprit, also replace the plug boots at the same time.

[quote:958d7c8847="David Satterley"]Hello,

I have a 1994 pontiac grand am with a 2.3 L SOHC 4 cylinder. Up until a few days ago, the car ran fine. Now, it won't idle, runs very rough and does not have enough power to move on it's own. I replaced the fuel filter, ran it completey out of gas and refilled the tank and replaced the map sensor with no help. We checked and cleaned the plugs and plug wires also with no results. Please help[/quote:958d7c8847]

[quote:c4eb7f79aa="David Satterley"]Hello,

I have a 1994 pontiac grand am with a 2.3 L SOHC 4 cylinder. Up until a few days ago, the car ran fine. Now, it won't idle, runs very rough and does not have enough power to move on it's own. I replaced the fuel filter, ran it completey out of gas and refilled the tank and replaced the map sensor with no help. We checked and cleaned the plugs and plug wires also with no results. Please help[/quote:c4eb7f79aa]

i have a 95 2.3 quad 4 also,, i had a big knock, i changed the head, the timing chain and sprockets, then checked out the rod bearings,, found those were bad,,, after the gm dealer had told me it was a bad valve... but i had a 93 toyota pick up 22R-E,,,, it had the similar problem that u are having,, i found that it was a head gasket problem,,,,,, i replaced the head and gasket on the toyota engine,,, runs like a champ now