lots of codes?

[basilv]

hi
I have 01 1.8 and i starting getting a cel light on about a month ago and my only codes were camshaft position sensor signal to high and catlyst system bank1 efficiency below threshold I cleared the codes and only came 2 more times in that month ..the light came back on and now i got another 3 codes wich are (manifold/barometric pressure sensor implausible signal) (bank 1 camshaft a intake retard set point not reached overadvanced) (manifold pressure/ boost sensor to low).... so today i changed the cam sensor because my buddy gave me one ,drove the car didnt erase any faults and checked the codes once more now another 2 came on which are (multiple cylynder misfire) + cylynder 4 misfire ...Does anybody have a clue what i should do before i go to the dealer and get ripped off? would aprriciate any help at all...

[Seerlah]

Pull the codes and go to here. They list possible causes and possible solutions for the codes you get. If the things they suggest don't work, then come back and maybe someone can grant better advice.