vatwell

New to this but hoping to find some help...I have a 02 outback with the 2.5 engine, manual transmission. A few weeks ago started running very rough, felt like it was cutting out or misfiring. Have put in new plugs, fuel filter, crank position sensor and now a TPS. No change. Code was showing misfire on cylinders 1-4. Hooked up the scanner during drive and it showed the TPS cutting out. Thats when we placed it. Odd note tho is that we ran a set of jump cables to ground the engine and it ran fine. Any ideas? Thanks!