2.4l idols rough, delay in acceleration around 55 mph

Hi All, I have a 2001 2.4l Grand am 73k miles and have recently done alot of work. I hit a big metal toolbox on the interstate going 70 mph. This ruined the whole front end (under the hood, no body damage) and my car over heated and blew a head gasket. SInce then I have done these things to my car
I have replaced,
ac condensor
radiator
radiator hose
sparkplugs and wires (plugs were completely melted)
head gasket
lifters
modulator
and yesterday I replaced the fuel filter. Ever since the check engine light came on when the modulator needed replaced the trac off light and abs light have been coming on every morning but go off when I turn the car off and restart. The check engine light issue has been resolved but now I have the "service vehicle soon" light on, Now the car now sounds horribly loud and when I first start it and runs loud for a few minutes and when driving when I hit about 55 mph and then again around 65 mph there is a hesitation with the acceleration. Two people told me it was the fuel filter so I went and had that replaced yesterday but it is still doing the same thing. It also idols rough, and the steeper the road the rougher, like i was sitting in traffic this morning on a road that wasnt flat and it was worse than what it is when just sitting in my drive way. Also about 3 weeks ago I wa backing out of a parking spot and the car just cut off and started right back up and it hasnt cut off since then. Anyone experience this stuff?? Thanks so much!!! I had no problems ever before but now have had nothing but problems since.... $2600 later my car still isnt right...... Anyone??

sounds like coil pack!! had similar prob rough idle loggy acceleration

Thanks for your response! I can not take it to see whats wrong until next Friday but am hoping I am not making the problem worse by driving it. Also this morning it took me a quarter tank of gas to drive 18 miles. Did you have that too? The gas is just burning up quick. Thanks again!

if its a spark issue its not hard to test yourself, just need a 13mm socket (to pull the 4 bolts that hold on the coil housing cover), unplug connecter at the end of the coil housing, pull straight up to get plug wires off spark plugs, flip over (use one bolt to hold it upside down out of the way), take off the plug wires, plug in electrical connector, install 4 conventional plug wires (long wires), connect 3 from the coil housing to the spark plugs, plug 4th one into the coil housing & spark tester ($5 - $10 at autozone) and ground spark tester to motor.

turn over motor to see spark, repeat thru all 4 plugs to see which ones aren't getting spark.

cylinder 1 & 3 are on one coil, 2 & 4 on the other
if your only missing spark on one cylinder its probably a bad coil housing

Is your catalitic converter plugged up? run the car at night then look under it to see if the exhaust is glowing red.

good luck & keep us updated.

I really really appreciate your response but I am a female (not that it is an excuse because even a man couldnt know I guess) and do not know what or where any of the parts you are talking about are. Thanks, I just have to take it somewhere....

Also this morning even with it eating up the gas I did not have any problems with the acceleartion?? I know it just didnt go away but it isnt consistently hesitating...... Weird!!! and the "service vehicle soon light" did not come on..... I just hope I dont end up stranded in the mean time..... I live in FLorida, and it is HOT, I am 6 months pregnant and still have not been able to get the ac charged from when I had to replace the whole front end (ac condensor). I was told $180 for the ac charge, they said they have to "evacuate the system" because it has been completely empty since December, does this sound right? Thanks, guys.....

Well I found out this weekend it was the catalytic converter, I just wanted to post this in case others have the same problem... I took it somewhere to get a diagnostic test done on it and the only code that came up was for a head light and an evap code which was due to the gas cap being lose. So they took it for a test drive and the mechanic came back and said he looked after he test drove it and the catalytic converter was bright red. I took it straight to the dealership and they looked at this morning and said that is it covered under warranty until 80,000 miles (Thank God I only have 74,500) but I also had a burnt coil cover, I had to pay for the coil cover but the converter is under warranty. Just wanted to post this in case someone has the same problem....In case you didnt know, it is under the manufactors warranty.... YAAAAH! Thanks for all of your feedback earlier this month as well.....