2002 Mitsubishi Galant P0403 CEL code

TSHEA0307

MEMBER
2002 MITSUBISHI GALANT
4 CYL
FWD
AUTOMATIC
170,000 MILES

Hi,
I have a P0403 on my car, and I can't seem to get rid of it. The car really isn't showing any signs of a problem. Gas millage is normal, emissions is normal, lots of power from engine. I replaced the EGR valve, still nothing. Now the mechanic is saying I may need a computer flash or whole new computer. My question is which is more likely? Also if it does need a new computer can I buy one from the junkyard? Any help would be perfect!

1 Reply

TY ANDERSON

MECHANIC
684 POSTS

This code implies a fault with the EGR solenoid is detected. The vehicle will self test the EGR solenoid current flow under certain condition for 0.02 seconds if it is consuming too much or too little current the check engine light will come on.
My first thoughts are either the new EGR valve is defective or there is a wiring issue (poor connection for example) within the EGR circuit causing the check engine light. It could be the computer but it is more rare to see a failure with the computer. My resources don't show any reprogramming updates. The Mitsubishi dealer is going to be the only place you could get a reprogram and they would have that information if that is the cause.

A junkyard computer may not work or may required programming to sync the junkyard computer to your vehicle. I would recommend getting a warranty from the junk yard (if available).