Ive got a code 12 which is EGR that only comes on like 5 min after i start the car. Sometimes if I shut it off and turn it back on it will clear and other times it wont. Its not the wiring. Just wondering does this code 12 refer to the EGR valve located on the intake manifold or sensors connected by vacuum hoses?

 

code 12 is the egr valve itself ( code 12=EGR valve no action ). Remove the egr and check to see if its clogged/frozen with carbon. IF so cleann out the carbon and reinstall. If not you'll have to replace the egr valve.