98 Chevy S-10 Misfire

[707lineman]

Hello all,  I have a 98 chevy s10 with the 2.2L engine.   Bought it from a previous owner and apparently it got way too hot.  We replaced the motor with another new 2.2L  We are getting a misfire on cylinder 1.   We have essentially  replaced everything,  from injectors, fuel pump, MAP, Spark plugs and wires, ingniton control module and coil packs, ECM, O2 sensors,  Currently gapped at 50 per hayes manual.  We have replaced plugs/wires, ICM, Coils multiple times  trying to diagnose this.  Trucks starts rough,  with misfire,  eventually smooths out,  take it for a drive,  no misfire.  Get to stop sign or pull back in drive way,  misfire on cyl 1 reaches up too 200 misfires.  Hook scanner to it, clear code P0301. Misfire goes away but then comes back.  Checked grounds  and they are good.  Fuel Trims are around 1-3 on short term and -5 for long term.  Cat converter was taken off. Anybody have any suggestions on what it could be?  We are at a complete loss with this

[Little Red Jimmy]

Could it be because CAT was taken off?