midlifecrisis

Ok this is getting more confusing for me. I had a service on the car a week ago and the garage doing the work had to order a pollen filter for me. I took the car in today to have it fitted and mentioned that someone on this forum had suggested a leaking air inlet tube. The garage owner said that was easy to check for and hooked the car up the the emissions analyser because he said that can tell them alot about a car.

Guess what? The emissions are spot on! No air leaks upsetting the emissions then. He said engine running fine and revved the nuts of the car and couldn't detect a misfire. He agreed that engine is slightly lumpy at idle but he thinks it might be the engine management that is at fault.

Would an ECU reset help and if so how do i do it?