98 Bonneville SE unusual problem, please help.
I have a 1998 Bonneville SE with 155,000 miles on it. The car has run like a champ since I bought it 4 years ago with 100,000 miles on it. Anyways, I have a random/multiple cylinder misfire code coming up on the car and symptoms of this are lose of power while going up small hills, and a jerking motion during acceleration. To explain further, while driving on the highway at 70mph if my car starts to go up the slighest incline, and I mean small, the car starts to slow down and I have to push the gas pedal in a little bit and all of a sudden it revs up to 3000rpm until I get to the top of the incline then it goes back down to 2200 rpm. Also the car does not idle smooth, the car fluctuates between 400 and 800rpm during idle and its totally random when it does, sometimes it idles smoothly, other time not. Some things I've recently done on the car are new IAC valve, new TPS, new sparks plugs, new wires, new coil packs, new intake manifold, new PCV, new MAP sensor, new tranny fluid, new fuel filter, oil change, and recently had the injectors removed and cleaned. Any suggestions would be greatly appreciated, I've tried posting this at other automotive forums but have received nothing but dumb answers, one of my friends referred me to this site and said you guys know your Bonnevilles.