Engine is misfiring

Question

Hi!
I have recently done a complete engine replacement job on my 2003 Altima it starts up and runs normal for about a few minutes while idle then starts to studder and miss I just put in new spark plugs today and still the same thing.

Answer 1

Right before it warms up and stutter does the engine run well if you raise the RPM up,? Just changing the engine the IAVL (idle air volume learning ) has to be performed. even if you use the same throttle body