Hi there from a cold and wet Cape Town, RSA. A quick question. I have a 2000 D2 4L V8 auto. 178k on clock. A mechanic mate and I did a basic service - the oil/ ATF/ Brake fluid change, spark plugs, air filter etc. this because i'm learning to do maintenance myself. however, since then there seems to be a less power and a popping sound on acceleration through the gears until the engine get warmed up. Please advise a newby!