New master cylinder now the car bogs

I just picked the car up from the mechanic after getting new clutch master cylinder and new ss line. Coming home cruising around 2k rpm and the car felt like it lost throttle. I didn't drive it over the weekend and just took it to the store and it did it 3 times. It felt like it was going into limp mode until you stomp on it, but no dash lights. What could the mechanic have done?

Check the vacuum lines. Likely missed getting one back on, missing a clamp, not on all the way, or cracked.

What vacuum lines and where do I look for them?

There's a vacuum line attached to the brake booster. Check it, and everything attached to it and the intake manifold

OK i'll check when I get home thanks

Just drove the car home and it went limp and the wrench (powertrain malfunction light) came on. Can this be from my recent mechanic visit or coincidence?

A vacuum leak can cause the wrench and limp mode.
Check out every vacuum tube and make sure nothing undone or broke