TIA for any help...
Car:
1995 Eclipse RS with a 97 420A engine(harness is good)
Symptoms:
-Engine stutters very hard in any gear...hard to even get into second/third
-clutch engages fine, then car stutters like it's not getting ANY gas(when gas is pushed even slightly above the minimum amount to keep it going
-just started today
-keydance codes 21(upper or lower O2 sensor) and 24(throttle position sensor)
-dead speedometer and odometer(code reader says speed sensor)...this happened before/during the test drive for inspection(was fine on the way there)

Recent work done:
-new clutch 25 miles ago(yes clutch fluid has been bled)
-new fuel filter 25 miles ago
-new breather filter yesterday
-changed gear oil in tranny(after clutch went in)
-inspection barely passed (speed sensor)
-filled tank up

Questions:
-could the speed sensor be causing this?
-worked fine yesterday...maybe ECU caught up with something a while after I reconnected the battery and drove it?
-can smell fuel underneath car, but no leaks...defective fuel filter...air hole in it?
-could breather filter cause anything like this?
Comments:
-I always let the car warm up for 10-15 minutes before I go somewhere
-After I put the breather filter on at work...it drove 1.5 miles home..no problem(lots of stop lights)
-Today, I could barely drive it...SCARY!

Sounds like the motor is choking itself. Check your o2 sensor, that CEL is there for a reason. Find out which one with a real code reader or take it to autozone if you can

As well, if you've installed a 97 motor in a 95 car, make sure you used the 95 fuel rail and regulator. if you didn't, you have no means of controlling fuel pressure as your regulator left with the 95 fuel rail.

Originally posted by DarkOne
As well, if you've installed a 97 motor in a 95 car, make sure you used the 95 fuel rail and regulator. if you didn't, you have no means of controlling fuel pressure as your regulator left with the 95 fuel rail.

good catch

Yes, good one.. but it's been done. You guys are not going to believe what the problem was!!! The FUC(ING breather filter!...No Shit! I took my car to work(Bodyshop) And I figured, "why not...might be..."
I checked the battery(12.74 volts)...replaced the little hose, and took it for a spin..I took it up through 3rd outside, with NO hesitation during acceleration! WOOHOO! Thanks for the quick replies guys!

my answer would have been "you DO have a DSM"