I scanned my egr with a snap on scanner - it test that solenoid 1 - off - solenoid 2 - off and solenoid 3 - off at idle - (1993 SSEI Bonneville) but on drive while driving the car, solenoid 2 and 3 are on but still Solenoid 1 is off - is this causing my car to run rough at Idle. I have replaced the egr valve 3 times, I'm now wondering if I should go ahead and change it again.

What symptoms if any do you have?

Is that one commanded on and not on?

runs rough at idle.

If you don't have an EGR code, look elsewhere.

Vacuum leaks, dirty IAC valve/passage in the TB, tune-up.

All done! no vac leaks and new wires and plugs- it seems solenoid 1 is not opening or turning on. per scanner

Do you have the FSM? Sometimes...certain valves and things only operate under specific conditions. Valve 1 might be commanded by the pcm to stay shut at the moment. While I'm not sure what it should be doing... I'm trying to ensure you aren't chasing something that isn't a problem.

WillWren has lots of experience with the valve you have... his first thoughts seem to indicate that it should throw a code if something is wrong with valve 1.

The only code its putting out is 26 QDM code - but other then that - no codes per scanner. I cleared all codes but still has that QDM code? Quad Driver Module I guess.

Is that a constant code, or does it only toggle when you put your foot on the brake?

(I'm going to be very hit and miss today due to WCBF kicking off, but I'll try to stay on top of this topic).

Keep in mind your car only uses 2 of the 3 valves. I don't recall which two until I can get to my FSM'* at home later today.

Yes constant code for 26 - It use to run great with the old EGR valve but failed on emissions, after replacing the egr - it never ran the same. rough - What does the quad driver module have in relations to the egr.