Expert: autohelp - 2/9/2010

Question
1990 Cadillac Deville with 185k mi. on it. Changed spark plug wires, spark plugs, egr valve, egr valve solenoid, eight fuel injectors, and an ecm computer because of a fuel inj. miss. Also, the Air pump was replaced with a new part last year.

Runs fine except an intermittent E49 code at idle after 5 minutes or so running after warmed up.

No driveability issues, just the service engine soon light pops up after all of this service.

Answer
You either have a problem with the air switching valve or the solenoids.

If you are mechanicaly inclined or know of someone who is, You will need a DIGITAL VOLT/OHM METER, Simple electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture. I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information necessary to fix your vehicle.