p0402 cel, missfiring?

[cashmoney37]

my 2000 mountaineer 5.0l, has a p0402 cel, my light came on today. my truck first started to run like crap then the cel started flashing. its now steady on. but the truck is idealing bad, and miss firing. i cantseem to find any info on the issue with the miss.

 

[sean99]

http://www.explorerforum.com/forums/showthread.php?t=82053&highlight=P0402

 

[2000StreetRod]

Stuck open EGR valve?

P0402 Exhaust Gas Recirculation Flow Excessive Detected

If your EGR valve is open the engine will run poorly at idle and full throttle. The EGR valve is vacuum controlled by the EGR vacuum regulator. You can disconnect the vacuum hose from the EGR valve and plug the vacuum hose. If the engine idles normally with the hose disconnected and plugged then your EGR valve is probably stuck open. You can test it with a hand vacuum pump.
EGR System O&T