IU'd look at the bad fuel filter as a first, then gas, then the intake manifold. A clogged fuel filter would definently starve the engine from having fuel, thus it stalling. Im not saying this is your problem, its a universal thing. Bad fuel would also do this. You can see if it is the intake manifold by starting the engine, and spraying something like carbeurator cleaner, wd40, or some other highly flamable spray thats not harmful to the engine. If your engine revs when you spray it, that would show your intake manifold is leaking, thus sucking in cumbustible wd40, and revving higher rpms than before. about the malfunctioning emmissions equipment...all I can think about is your o2 sendor(all Ive had to deal with), I haven't known it would be a reason for stalling, just bad gas mileage and performance. let us know what you find out <img src="/forums/images/graemlins/coolg.gif" alt="" />