I beg to differ....
If your idle didnt degrade when the EGR was open, your EGR wasnt working properly. There's no way an open EGR at idle would be near smooth enough to pass an inspection.
Anyone wanna test this: With the car idling, apply 6" or so of vac to the EGR (you can connect a rubber hose and suck on it even). The car's idle will go right down the crapper.
For Mr Duncan, if you notice your idle go to crap when you suck on the EGR nipple
then we'd want to check your vac line, EVR and position sensor. The Valve (a slave) might be fine but it's not getting the correct input.



