Unusual misfire situation...

[Mechanician]

CKP sensor relearn maybe worth a try.

 

[clinebarger]

CKP sensor relearn maybe worth a try.

Maybe, But I didn't read where timing components were disturbed/changed.

 

[Starving Electrician]

Maybe, But I didn't read where timing components were disturbed/changed.

They don't have to be to be starting to fail.

 

[clinebarger]

Just about all OBD2 GM's will set a Cam/Crank Variance not learned DTC if it's out a few degrees from it's last learned value or the ECM doesn't have a learned value from it being reflashed.

GM has a pretty good live data misfire monitor.....All this is based on a pending P0305, Might be a good idea to review the misfire data!

 

[Mechanician]

Maybe, But I didn't read where timing components were disturbed/changed.

They don't have to be, to possibly cause a mystery misfire.
It would be easier than taking more things apart to check them.

 

[mattd]

If he can “feel” it, it’s not a misinterpretation of data from the CKP sensor. They will usually cause “phantom” misfire codes. Not ones that be felt, per the OP

 

[Mechanician]

If he can “feel” it, it’s not a misinterpretation of data from the CKP sensor. They will usually cause “phantom” misfire codes. Not ones that be felt, per the OP

True - it's been described as "slightly feel."