1994 Honda Accord Engine Hesitates for First couple Miles.

I have a 1994 Honda Accord lx 100,000 miles. I recently installed some aftermarket headers after my originals had a small crack/leak. I pulled the fuse for the ecu as well as disconnected the battery for a min to reset the ecu. Now, when I first start the car, for the first couple miles while driving conservatively the car hesitates. Once a mash on the throttle a little, or drive a few miles, the car will drive normally. I still have the cat installed so there shouldn't be that much of a back pressure issue. I'm thinking it has something to do with the MAP sensor. Any thoughts on how to fix?

PS. I really don't think this has to do with the problem but I changed the oil at the same time with a different brand filter then usual and it seemed a bit larger then my old one.