Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
I am sorry for the long wait
can you confirm the ground on the front of the right cylinder head are clean and tight ? if the ground is not on the front of that right head then the ground is on the back of the cylinder head G103 as seen here in this picture
no rush at all
can you monitor like computer data especially current cylinder misfires and when it is acting up does the live misfire show just # ***** cylinder misfiring ?
with this being it seems 2 specific cylinders when it acts up we need to go after those cylinders
this had a brand new fuel injector on # ***** and or # ***** cylinder ?
that's where i was going with this
swap # ***** coil with # ***** coil
if it still does this with the 303 code with a new injector and coil and or coil swap the only thing left and is somewhat common is a bad crank sensor located behind the starter acting up and firing # ***** cylinder at the wrong time which will cause this issue
replace the crank sensor and perform the crank sensor relearn with the scan tool and see how it drives
a shop to change the crank sensor and relearn the new crank sensor would be 1.0 hours of labor X's the shops labor rate and the crank sensors can vary for $ 50 to $ 75 give or take