Saturn Repair: engine swap, coolant temp, coolant hose

Question
Swapped a 96 saturn 1.9L dohc into a 95 1.9L dohc. Changed all the sensors from the 95 engine into the 96 engine. It now idles rough and starts smoking after it gets warm.  Any idea what is causing it to smoke? Also changed out the intake manifold.  

Answer
Hello,
 For starters, '95 and previous was the first generation of Saturn (in the SL series).  '96-'99 was the second generation.  If I had to shoot from the hip on this one:
1. The ignition coil was not the same on the two different year models.  One is a two-plug, and the other('96-'99) should be a single plug.  If you have the correct coil for the wiring harness that you are using, make sure the coil assembly is grounded to the front of the transaxle via four long 8-mm bolts.  
2. The '96-up uses only one ECT (coolant temp, driver's side of head behind coolant hose.)  ECT sensors are notorious for causing problems in Saturns.  
As far as smoke after warmup goes, I can't tell you.  Maybe you have some stuck rings (happens alot with junkyard motors) or some bad valve seals.  
Anyway, Hope this helps!