The code needs to be read because there may be a problem that has taken time to notice. As far as the tune up being 2 years ago, check for arcing from the plug wires, cap and rotor condition. After market parts never seem to last as long as factory parts. Finally, the man who checked the computer mentioned about the gas cap. What he is refering to is an EVAP code that would indicate a leak in the fuel system (not gas but fumes). If there is a leak, it would set a code, and it could cause a vacuum leak which inturn could cause a rough idle. However, without knowing the code, that is nothing more than a guess. Did you take the truck to a mechanic to have the computer tested?
Friday, January 23rd, 2009 AT 3:20 PM