This is a 1990 F-150 with the straight six 4.9 and a manual transmission. It will stall at an idle, and when I'm driving and shift gears, the engine will maintain it's RPMs while the clutch is in. It sucks to try to keep the engine running by giving it gas and trying to downshift and stop at red lights in rush hour traffic.

Replaced fuel filter... is it possibly IAC or EGR???

sounds like it may be you TPS.

I would check the iac first

Thanks for the replies, I tried the IAC yesterday... no go. Will try the TPS next.