F 150 ege valve problems

I changed my egr valve and now the truck runs even worse. I get a po402 code (egr excessive flow detected) code now. The auto parts store (advance auto parts) said the new EGR may have been defective and ordered me another one. Any other suggestions?

NOTE: I do not know the original code than called for the egr valve replacement.

2000 f150....4.2 v6 engine

Thanks in advance!

Excessive flow through EGR ,is a symptom of a bad DPFE sensor.

Thanks danielsatur! a few more questions if you don't mind.
The check engine light went out and the engine seems to run better now...some hesitstion but nothing like before. I probally drove 75 miles with the check light on before it went out. Is this normal...I have heard that some cars need to have the computer reset by a dealer? I am planning on changing the dpfe sensor...the engine ran fine before and I,m hopeing that the hesitation will end after I change the sensor. Agree on disagree?

Thanks!

After troubleshooting, you should of cleared the code, the Emission Contol Unit (ECU)
cleared the code itself, after it went through it's drive cycle.
Your Emission System is ''ok'' , if no DTC's exist.

See http://www.automotiveforums.com/vbulletin/showthread.php?t=970953

Thanks again!