My 2003 coupe has piston slap. It sounds like a diesel engine at start up and when cold. After warming up however, I still hear what sounds like a noisy valve train under acceleration beginning around 2200 rpm through around 4000+ rpm. Is this still the piston slap, or do I have faulty knock sensors? I've read threads on piston slap, but most say the noise goes away after warm up. Will faulty knock sensors throw a code?

Thanks for any help!