ive officially replaced and gone through every bit of this friggin APC system and still stuck in base boost. today i got around to what i thought was the last piece of the puzzle.. the overboost switch under the dash (not fuel cut-off). ive gone through every vac line / sensor etc. before i replaced the overboost sensor , i disconected the hose from the APC system to the wastegate and verified that i get full boost (im tempted to leave the friggin thing off). the solenoid chatters when tapping the knock sensor , i swapped out the APC box with two other replacements to see if it was that... still nothing, APC fuse is fine. i checked and adjusted engine timing twice , replaced the dizzy and vac advance module , had the knee bolster off today and checked the brake switch and any othe wiring.. all seems ok. what the hell now!! and on top of it , now when i turn the car off , put it in reverse (with clutch in ) take out the key, the damned reverse light still stay on !! could i have dislogded something that causes this condition now?