'96 2.5 L cranks easy and runs smoothly for 45 seconds. Then runs rough for about 30 seconds with rpms going up and down after which runs smoothly again. Very repeatable every time when cranking cold. If driven during this warm up, it will lead to lurching and bucking. I know the computer is going through some startup cycle but no codes are generated and it runs good afterward. Already changed the TPS thinking that was it. Anyone have any ideas where to look next?

Did ya check for codes even if lights not lit ?

Yes a couple of times. All I get is the battery disconnect code for the last time it was unhooked .

Anyone have any ideas? Thanks in advance.