Engine is making clicking sound and has poor performance

Acceleration and engine noise after recall work by Lexus problem with hesitating acceleration and engine clicking sound. I brought in my car for recall to tighten the fuel-pump pressure sensor after I got the car back, the acceleration was hampered with hesitation and the engine developed clicking sound similar to the loose valve lifter syndrome of the vantage cars of the 60's models. Can you see a connection to the events I described? Can you give me an idea as to what might have happened? I have 2009 Lexus IS-250 with a V6 engine.