I have a chevy s 10 pickup v6 2.8l that i have been having problems with. the truck wont pass smog was way off charts so gave it a new oil change and spark plugs. also adjusted the carburator. it now passes on everything but Co2 at hi speed 2800 rpm. 2.69% 1.2% is what is needed to pass. can anyone help me with this problem. just cant seem to get it down another 1.4% :( thanks in advance