ROOT

Hello, I have a 2000 silverado Z71 and last night I started it and it started idleing rough. I got about a mile down the road and the service engine soon light came on. I stopped by autozone and they hooked it up and the code said cylinder 6 misfire. I replaced all the plugs and wires but i didn't change the way it ran. It idles real rough. I took it to the dealer and they said it was a P0300 code and that I needed to replace the fuel injector because it failed. Every plug has good spark so they say it is not the coils. Does this sound correct to everyone???

maxwedge

Sure.

2000CAYukon

A misfire can happen if there is no spark at all or no spark when it is suppose to fire. A misfire can also happen if there is no fuel in the cylinder when the plug fires.

Your 5.3 has coil packs, so if the coil, plug and wire are working properly, then it makes sense that the injector is bad.

Put a timing light on the #6 wire. It should flash with every spark. If the light does not flash, the coil pack could be bad.

Another trick is to swap the #6 injector with #8 or #4 to see if the misfire follows the injector.

//2000CAYukon

ROOT

Thanks guys. I've been burnt by the dealership before, so I thought I would check with you guys first.