1-2-2 is air intake temp sensor, which is, I believe, either the EGR system temp sensor, or the ambient temp sensor. The EGR system makes more sense in relation to your problem, since the ambient temp sensor is for electronic climate control. As I'm sure you know, sulphur smell indicates a running too lean problem. If you could get somebody to stand behind the car while you do a brake stand (accelerate hard with your foot on the pedal)to verify if exhaust pressure increases with acceleration or leaves on acceleration this would help rule out a clogged exhaust. Not just the cat gets clogged, baffles fall apart in the mufflers as well. However, I'm leaning towards low fuel pressure, i.e. fuel pump. If the car will idle beautifully...forever...all day long in fact...but falls on it ass on accell...it's usually the pump.