i have a acura tl 2.5 1998 and i went for my emmisions test and failed.. i have a engine light on and i read the codes with my mac tools scanner and the code came up as p1491... egr valve lift i dont know what to do .. please help

 

It may be an electrical/sensor problem since P0140 is EGR insufficient flow, but I would just go ahead and clean EGR/intake chamber because it can only do good and no harm.

 

This code indicates "insufficient lift of EGR valve". What that means is the ECU commanded a certain lift of valve pintle, but did not measure adequate lift. It could be damaged or disconnected vacuum line, bad vacuum switching solenoid (blocked or stuck), or faulty EGR valve.

Check all vacuum lines to the EGR and EGR switching solenoid valve.

Check first for vacuum to the EGR valve. There should be none at idle and vacuum available above 2000 rpm w/ engine fully warm.

good luck