01 buick 3.1L engine bogging chugging pulled 1406 egr code new valve the same

Question

checked voltages, coil impedence before installing new egr
valve still get intermittent check engine and 1406 on hard

Answer 1

P1406 EGR valve pintle position circuit

Recheck the EGR to see if carbon has got stuck in there clean and  reinstall it. If there is no carbon that has cause this condition , You will need to refer to a TSB that Buick has produced about this code condition TSB # 01-06-04-018A what this TSB is about is the EGR valve position that does not correlate to the PCM calibration values.and recalibrating the PCM. You need to inspect the EGR pintle first.