Stalling, no power, jerking, intermittent

It could be a number of things, first change fuel filter with 150,000 and being a 2001 the first thing I would look at is the fuel. There is a additive that I use on our 1994 Firebird that sits for a while it is what they call sea-foam. it goes in the fuel tank and helps with junk that ethenal produces. It happened to me once where the fuel screen on the end of the fuel pump got clogged up and limited the amount of gas. It probably is the cheapest way to start.