Spring of 04 my 97 VW Jetta standard transmission kept stalling on its own-the RPMs would jump a bit without me pressing on the gas and while idling, it would just fail. I had my catalytic converter and two o2 meters replaced, I was told this would do the trick. On my way home from my mechanic in Alexandria, VA, after they had my car for a WEEK, the car stalls in traffic in downtown DC. Since then I've replaced both of the o2 meters twice, each time paying a good chunk of change (I've paid about $400 per o2 meter). I last had them replaced at the beg. of April, and 20 miles into my drive back to DC (I'm from NH) the check engine light came back on.
Now I'm trying to register my car in DC, where you have to pass an emissions test, and guess what-I failed.

My question is, is it worth it to keep replacing thesse o2 meters or is it time to say goodbye?

--I was told by the mechanic at the DC inspection station to see a VW dealership who'd be able to detect if something else was causing my o2 meters to blow...is this worth it as well?

the o2 sensors wont make you fail the catalytic converter will, the o2 will make your gas mileage drop mainly,

if the check engine light blinks while driving, one of two things cat or the coils. but since you stall it might be the ignition coils, test it by turning on the car and getting a spray bottle with clean water, turn on the car spray a mist over them if they arc the coil is bad, this causes it to stall or become sluggish. does it stall in dry weather or mainly humid and rainy days?