spark plugs

How about a trip to the local AutoZone and have them scan the car for stored codes..Then One Could FIX it! NO More Guess Work
Have you checked for vacuum leaks?Which are a very common cause of the malfunctions you describe.
Find a shop with a good scope and run a test on your ignition system to see if it is doing as it should.Hate to say go to a shop,but as above you have spent alot of time with no results, so maybe this one is out of you're reach.
However i'd start with the leaks and get your own code reader they are only 49 bucks for an obd can 2 reader at harbor freight tools and worth their weight in gold.check the maf it could be bad but then it would show 70 and 73 codes,what codes did you pull with the check engine light either active or stored as pending if you have not erased them yet?
on a scope you can check the maf with these perimeters
High Lambda values at idle (lean air-fuel-mixture)
Engine hesitation at high RPM
Engine misfire at high RPM
Engine going into limp-home mode at high RPM
keep us posted and good luck
ohlord
without the codes, nobody can help you.
David





