1998 Ford Taurus Hesitates, rough idle, low power

I recently bought a 1998 Ford Taurus. It has the 3.0 OHV engine. I know no history on the vehicle, as I bought it to repair.

When I got it, the CEL was on, it barely idled, had poor acceleration, and was backfiring a little under load.

A scan tool showed several codes, IAT sensor out of range, MAF problem, Cam Position sensor, Misfires on basicly all cylinders, and system running lean.

I replaced the MAF and the Cam sensor, as well as changed the sparkplugs, wires, and fuel filter. The check engine light went off, and it does run better, but it still idles poorly and has slow acceleration.

It feels like it is out of time to me, but I haven't checked timing. Also, the exhaust system is somewhat damaged with most of the exhaust coming out the flex pipe (broken). I checked and it has good fuel pressure at the fuel rails.