128k miles, have gone thru all diagnostics. In park at all rpms no issues. Once auto trans is engaged, rough running ahead. one code says trans slippilng, could this contribute or not.

 

it sounds like you dont have a missfire but a slipping trans. when the trans slips it will cause the rpms to fluctuate.

heres a video of my blazer slipping (same trans)


also pay attention to where your posting, this is the 5th gen section 2010+.

 

Thx for the tip, sry for the section post

 

would the slip cause the misfire codes?

 

no what are the misfire codes

 

305, cyd 5 misfire

 

plugs, wires, coil, injector, sticky valve