Neverm|nd

I imagine this must be a somewhat common problem but have not been able to find anything in my searches, so here goes:

Not too long ago (last year) I replaced the exhaust manifold on my '96 Del Sol because the feeder pipe had basically rotted out as well as the bolts on the manifold itself.

Ever since then I've been having perhaps two separate idle issues. For one, I should say the car is a manual-- however except for the bit I will express at the end I can't say I have been able to reproduce this issue with any regularity.

Issue #1: Usually after driving for awhile, I will clutch it (either to break at a stop sign, or just coast) and the idle just drops right off-- The car *stalls*: Though note this doesn't happen *all* the time and otherwise will idle fine. Further, when in gear the engine runs really smooth, no problems.

Issue #2: When I hooked it up to the OBD, a MAPS sensor error was coming up, so I replaced the MAPS sensor (and the fuel filter -- Pump sounds like it is running fine before ignition). Again, only *occasionally*, car will crank and turn over, but immediately drops out of idle into a stall. Somehow, giving it gas during will only barely help, or maybe it sputters about for awhile, but otherwise seems unresponsive. However, once it has decided it is finished with such a temper tantrum, it will run just fine.

Finally, *big spoiler*: I did not have the second problem until just recently, but for reasons I cannot explain (as I live in the North East), though I had idle problems last fall, in winter, cold, dryer air *the idle issues went away(!?)* only to return in the spring when things warmed up.

Little lost on this issue or what I should check at this point so I would appreciate any advice.