Bad Mass Air Sensor??

[motox852]

I think I have a bad mass air sensor. My wifes CEl came on and autozone did a diagnostic on it and said it was the MAS, hopefully this is correct. I'm putting a new one on this evening. The car had rough idle and occasionally dies at a stop light. Anybody had a MAS go bad and what did your car do? Thanks!!!

[shorod]

What year is the LS, and is it a V6 or V8?

From the symptoms you describe, you should also check for loose vacuum lines, loose air intake hose, restricted air filter, and EGR valve and passages. Does the car run fine at higher engine speeds, just not at idle? If so, my focus would be on the EGR valve initially. If the EGR is not closing completely at idle like it should, it can cause exactly the symptoms you describe.

-Rod

[dirtbikekid]

WEll, it wasn't the MAS, light still on, they check it and it says code 0173(I think) which is O2 sensors bank 2, I got both to replace and the guy told me if that wasn't it, that I could return them. Would bad O2 sensors cause this problem, that is what the code reader told us anyways, thanks for the help.