2006 Chevy Malibu 02 sensor?

[FROGMAN]

I had the car run through the dealership computer for problems. Was told to change the coil pack and the check engine light would come off ! It did ! until I got home. I always thought it was the O2 sensor. so my question is: If I unplug the sensor and the car still sputters and shakes ( And often stalls at stop signs) Can i assume that it needs to be replaced. This diagnostic test was $140.00 the coil pack was $50.00 and didn't do anything but lower my bank balance.
It runs fine until it gets warmed up then sputters, and if I'm coasting down a large hill the check engine light shuts off until i have to get back on the gas pedal !
2.2 Ltr Ecotech
4 cylinder

 

[michael]

O2 sensors don't have enough control range to affect the drivability of the engine. Translation - it won't make your engine sputter. 4 years is also too early to expect O2 sensor failure.

It seems the diagnostic test was pretty bogus besides being expensive. It sounds to me like the EGR valve is leaking exhaust into the intake when it is not supposed to, like on deceleration and idle. Cleaning the EGR valve would be a good thing to do at this point.