I just replaced my plugs and wires in my 03 chevy Blazer 4.3l V6. and now it runs worse then before i changed the plugs. i dint change the order of the plugs and it has no power now, and the service engine light blinks as i drive.
CAN ANYONE HELP??????

were the plugs gapped and installed correctly? tightened, but without overdoing it?

make sure the connections of the wires on the plugs and at the ignition coil are snug.

check, double-check, then check again, the firing order.

03.... did that stil have the distributor system?
anyway, make sure your firing order on both the distributor(or coil) is correct along with the engine. go to your nearest autozone or advanceauto, and have them run an OBDII "check engine light" scan on it. its free, and chances are you could fix it right there. once you have it scanned(they also loan the scanner out) post what codes you are pulling with it, and we can halp out better. also, did you di-electric grease the wires? are they pushed on all the way? is your fuel filter dirty? air filter? throttle body?

yes they were gapped right and installed sunggly and not to tight. firing order is correct and wires are snug. im at a loss for whats going on. I'm gonna get the codes tommorow and see whats really going on. Sucks that this happens on Christmas day when nothings open.

Well today i got the problem solved ther code revilleda bad plug so i retured the ones i had for some new acdelco double platnums and bingo the problem was solved. THANKS GUYS!!!!!