97 gmc codep0403

I have a 97 GMC K1500 and keep getting code P0403. Some guys at work said it was the O2 sensors. Went to autozone for the free scan and they agreed. After changing all four at a hefty price the same code came back. After looking up the code on the net it said EGR circuit malfunction. Can anyone help me with what this means before I go broke swaping parts

There is no code P0403 in GM diagnostics for 1997...recheck the code and get back to us

Went back and double checked. the scanner comes up with 403. below that or maybe above the tech at autozone wouldnt let me get to close it had P0. P= powertrain 0= genric not manufacturer specific. is there something else I should be looking at.

P0403 is a exhaust gas recirculation circuit malfunction- check out your EGR valve, it's someplace to start. :2cents:

well it makes sense to me to but how do you check it. mine does not have any vacuum hoses on a connector. I've read where other people have said to pull it off and clean it but not sure how to do that either

I had a similar problem. Check this post: http://www.automotiveforums.com/vbulletin/showthread.php?t=181647
Also, do a search on GM EGR valve, and you will get LOTS of info on them. There are some tests you can do while they're still on the vehical with a voltmeter too. My just needed cleaned :)

I disconnected the EGR after having it reset at autozone. Drove around half the day with no problems except EGR light came back on emediately. Went back to Autozone for a scan came up with P1406 which means it could'nt recognize the position of the sensor. Pulled off the EGR valve scraped off the heavy deposits sprayed it down good with some carb cleaner and now runs great. Thank you for all of your help.

Are You Sure It Is Not Code P0304 Which Is Cylinder 4 Misfire?

Newbie this is 2 years old!