So my CEL came on last week for my O2 sensor. I'm going to get both of them replaced next week just to be safe. My question though. Today I started up my car and right after it started up it shut off.. I started it up again and it was fine but the idle was a bit jumpy. Are these common issues related to the fouled O2 sensors?

 

get the fault codes you could be changing the o2 sensors when it could be something else like a vacuum pipe/gasket leak

 

Sorry I should have mentioned I had my mechanic check for fault codes and he said it was the O2 sensor. I also tested for boost leaks and there are none.

 

something doesn't sound right there mate (why did the CEL go off) and what was the code the reason I ask is because its probably the precat o2 sensor just starting to go out of range which could men the cat could be the fault ( the code is important in diagnosing this problem )

 

Hmm, ok I'll try and get the codes from him. THanks

 

Bad 02 sensor(s) shouldnt cause the engine to stall. A bad engine coolant temp. sensor can do that, and someitmes triggers an 02 sensor code too... (even though your 02 sensors might be fine and you dont have an ECTS fault code)... Both parts, when bad, will cause you to run rich-at least at startup which causes the engine to get flooded and stall. A bad ECTS will make you stall more than a bad 02 sensor would-if at all, and is a lot less expensive to change. If I were you, id try replacing the ECTS and see what happens.
Fault codes arent always 100% accurate... But they at least will lead you in the right direction.