So I have been dealing with this issue for over a year . Even changed motors (due to other reasons) & the problem is still happening. When I get to over 65 mph the stabilitrak & traction control lights come on & my check engine light starts flashing . The rpm’s also run high from 1st to 2nd gear, but shifts clean after the lag.. We have changed everything from the coils to spark plugs , fuel injectors, & wires along with the air filter. Even changed the purge valve, cause it has a evap code as well. Iv taken it to the dealership to get diag test , town mechanic's around me . & no one can figure out this issue even after thousands of dollars now… idk where else to go with this …

 

Vehicle details would be helpful

 

It’s a 2008 Tahoe LTZ