cel p1400 "manifold differential pressure sensor" now i know how to test to see if its bad but one of the things ive noticed is when i disconnect the battery to clear cel car runs great but it obviously comes back on and car still runs fine while its on but sometimes when it comes back on i have what the guy i bought it from calls "random misfire" which only happens when theres isnt any acceleration or decceleration meaning as if the car was set on cruise control then i push in the clutch it goes away for a sec and then comes right back and it doesnt always do it after cel is reset is this something "mdp sensor" related? also does anyone have a working mdp sensor for sale where i can avoid spending $140 on a new one?

i think i have a couple of those sensors laying around, but i have no idea if they work

trying to pass smog or something? That sensor doesn't do anything but check to see if the EGR is working. It doesn't effect the cars performance or gas mileage.