1996 Honda Accord 4 cyl Front Wheel Drive Manual 112k miles

I had a bad cylinder in my old engine and it was obviously running extremely rough so i purchased a used engine with 112k miles on it from a certified wrecker. Had a local shop install the engine, swapping all components except for coil and injectors.

After R&R new engine starts and idles rough but has even less power than my previous engine did on 3 cylinders. All cylinders in new engine have over 160 lbs and has spark and fuel. Timing is checked. Computer says the O2 sensors are out on both manifold and catalytic conv. and that it is running too lean.

When driving it feels like the engine is fighting itself for power... revs, but has no increase in torque or acceleration..
Had catalytic converter checked and even went as far as to drop the entire exhaust to see if that was restricting it but no change in power.

Could this be a fuel pump issue? Throttle positioning sensor?
Where should we start? I'm at a loss...

 

welcome to the forum, wondering if the engine you replaced is from the same year, and same make engine. Ecu sometimes are not the same for a different engine. Also have you changed the 02 sensors, these will tell the ecu to not put fuel to the engine if not properly working.
When your engine went bad, did the engine light come on indicating the sensors were bad? or no engine light.

 

Engine is the same year... All numbers match.. just checked that at the wrecking yard last night..
I haven't replaced the 02 sensors yet because they are kinda spendy and it seems like they wouldn't go out while it was getting the engine swapped...?
the check engine light came on when my engine went bad but due to the fact that 1 cylinder was running at barely 30 pounds i didn't even plug the computer in..

 

forgot to mention, have you tried resetting the ecu by pulling the 15 amp fuse for about 5 min, or disconnect the neg terminal for the same.