i have like grey interior. the leather is a dark grey and the trim is a darker grey color..

 

The #1 cylinder is the one closest to you when standing in front of the car.

 

My son has a Audi A4 that the fuel pump went out on. It was replaced and they left the exhaust hose unhooked when he picked up the car. He immediately knew something was wrong and returned to the mechanic. They fixed the issue. However, now is check engine light comes on each time he fills up the car and the code at autozone is turbo.

What have they done and how do we fix this?