96 5.0 is cutting out in town on acceleration, and it wast doing it when I was running open headers yesterday but today I had a body lift and te exhaust done..

 

It's doing it mostly in the city but does it on the highway too.. It's also getting terrible gas mileage and the idle is seems really low

 

You did put the oxy sensors back into your new exhaust, right? All you need is the front (pre-cat) ones. The ones after the cat can get tossed into the scrap pile with no effect on the engine but you'll get a fault code since the computer sees an open circuit.

 

I've got codes for crankshaft position sensor, air intake thing and aecondary fuel injection malfunction

 

the smell was both in the engine compartment and exhaust pipe and smelled like burnt coolant