[Dog5ohfun]

Code 11 is system pass code and everything is fine. 31 is a stored code from when the engine is running. It has to do with your EGR valve on the intake next to the throttle body if you didn't know. The signal voltage is below specifications or the valve is not in its normal closed position or the EGR vacuum regulator has a selenoid circuit problem. If you need a temporary fix you can remove the EGR valve and clean it with carb cleaner inside to remove the carbon build up. When you spray the cleaner in actuate the plunger until it is easy to move. It is quite stiff at first. Then let it dry, then reinstall. This is a temporary fix, lasts a few months if I remember right. The valve is probably worn out if it is original. You could skip the cleaning and just get a new one. I think they are somewhere around $90. Good luck