2000 z71 5.3 code
 

Hi people--I have a po300 code with ck eng lt on. It only misses at idle, you can't feel it above 1000 rpm or above. I know this is a tough one as it could many different things. Have only had a bad coil in 97,000 miles. Have changed plugs and wires at 75,000. where should i start?

thanks

Re: 2000 z71 5.3 code
 

Hi and Merry Christmas

The 0300 code refers to intermittent misfire detected by the O2 sensors....

Follow the check list in order.

Faulty spark plugs
Faulty spark plug wires
Faulty coil
Vacuum leak in intake system
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Stuck/blocked/leaking EGR valve / passages
Faulty catalytic converter(s)
Faulty camshaft position sensor
Burned exhaust valve
Defective computer

As you mentioned it only misses at idle I would be looking for a vacuum leak as a priority.
:chevy::chevy::chevy:

Re: 2000 z71 5.3 code
 

update---moved my tk for coming snow and the eng lt went off and the miss did also but came back but no eng lt.

Re: 2000 z71 5.3 code
 

still running good no eng lt no miss?