Hey guys well I finally got my car tuned by a profesional tuner and my 3.73 gears installed. He used HP tuners (no wideband) and about half way home on a 2 hour drive I pop my Service Engine Soon light......So I read the codes when I get home and they are p0171 Bank 1-4 "System too lean"... It has a code for bank 1 and bank 2 but the car runs and drives fine!! So why is it doing this and could this be a major problem? And how do I fix it? I called him after it happened and he said it was the tune. So I am taking it back this weekend..... What should I have him do to fix this?