Recurring problem please help!!!

Guys,

Sorry to repost about this problem, but I havent made any progress and am seeking additional input.

I have a 96GT with a '00 GT motor and over the last few weeks have had a crazy problem that has made the car run like crap to the point where I cant drive it anymore. The cur bucks like crazy, in any gear. If I try to give it gas it just shudders and bucks - kinda like hitting the rev limiter. I pulled the codes on it and got the following...

P0320 - Ignition speed sensor
P0171 - Bank 1 lean
P0174 - Bank 2 lean
P0141 - 02 sensor heater circuit

The car is lowered and the h-pipe had taken a beating over the alst couple of years, but I took the car to my shop and fixed the exhaust leak that had occured. After fixing the leak, the car ran fine for a little while, but slowly reverted back to the crazy bucking Im experiencing now. It was weird at first because the car would run fine when cold but as it heated up the bucking would start. I tried replacing the crank position sensor but with the new sensor the car would just drop rpms and die while in the middle of driving, so I put the old one back on and still have the bucking present. I think the P0141 is a sensor for the REAR passenger 02, but my rear 02 are both brand new. My MILs are worn, but I dont think bad MILs would cause a driveability problem.The car also has a new fuel filter, so the bucking isnt from a clogged fuel filter either.

I dont know what to do, my local dealer (Galpin Ford) wont do any engine diagonstics cause I have aftermarket mods. Has anyone had similar problems or does anyone know what is wrong with my car? Please help, any input would be appreciated.

Thanks,
Eric

Thanks for the input, but I junked the plasma booster a long time ago, a few weeks after I first got it - I forgot to take it out of the sig. The crank wheel has the proper clearance - checked and rechecked that with a feeler gauge - if I remember correctly it should be .12 to .80 according Steeda. I dont even know if I have my old MAF laying around, but I've cleaned the C&L I have and no change. Plus Ive had my current MAF for 2.5 yrs with no problems. And finally, I did reset my timing backt o 10* a while back as well - due to *****ty CA gas. I have a feeling the P0320 code is the key here, whatever is causing that is probably responsible for all of this.