I just received a rebuilt engine for my 2001 Toyota Camry CE 2.2L. Threw it in and used all new gaskets for water pump, intake manifold, head, etc. I go to start it up and it starts smoking really bad, idles rough, stalls and throws misfire codes. So I take it back apart just to see that there was coolant in all 4 cylinders. So I replace the head gasket and get all new head bolts throw everything back together, torque to spec + 90 degree, get everything timed and thrown back together with again a new intake manifold gasket, new oil, everything. Head to start it and it sounds good for the first 3 minutes or so and it idles nice. A couple minutes later it starts to idle rough and then the idle drops and it dies. It again throws misfire codes for cylinders 1 and 2. All plugs have spark, coil packs are good, wiring is right, block and head don't seem to be warped checked using a machined straight edge. It is most definitely getting fuel I replaced the fuel pump not that long ago, fuel relay is new, fuel rail isn't clogged, injectors working perfectly tested each individually, even checked fuel pressure and that is perfect. Good compression in each cylinder. Did a cylinder leak down test, doesn't seem to be any leaks. I wouldn't think it would be a failing O2 or cam sensor because I would definitely get a code. No idea what it could be. Any clues?