2003 Chevrolet Impala Q&A

2003 Chevrolet Impala Question: my check engine light blinks when i go over 30 mph..runs kinda rough and stalls

took it to auto zone and they said it was the #3 cylinder misfiring..so i changed fuel injector and still blinks over 30 mph -
Answer 1
did you repl plug and coil also. what lead u to repl inj 1st. they are almost always good over plug and coil -
Comment 1
they said that the injector might be bad so i replaced it and the plug and coil..but it still confuses me because even if i put the car in neutral and coast down the hill..right at 30mph the check engine light starts blinking -
Answer 2
A misfire is almost always caused by not enough fuel or spark. You will need to determine which is the cause. -
Comment 1
the spark plug was changed...the old one had black oil on it looked like -
Comment 2
re-check the new spark plug after a few hundred miles and see if you are still getting deposits on it.Make sure you got OEM type plug! Reply with what you find. -
Comment 3
still does it....plug is still oily lookin -
Answer 3
Most likely coil or spark plugs. -
Answer 4
The 'blinking' check engine light is a sign that your engine is running poorly enough that it IS doing damage to your converter (and most likely other systems as well).If you're doing the 'repairs' yourself , spend money on a correct diagnosis before buying more parts. Codes tell you what system is being affected many times , not that a specific part is bad (although many do).DO NOT HAVE IT DIAGNOSED BY A PARTS PLACE. They sell parts. A repair shop diagnoses and repairs cars. -