you should have posted the problem(s) earlier before the head change. People like xulfiqar, ser_gtr, rustam54 and few more could have helped you correctly identify the problem & remedy as well.
did the person 'USTAAD' doing the job replaced the Intake & exhaust manifold packings to oem new or simply glued the older ones, check for exhaust / intake manifold. I suspect packing / gaskit damage for noise and delayed acceleration.