Hesitation, flat spots on WOT?
 

Hi folks
As indicated I've noticed slight hesitation/flat spots when I nail it from around 2000rpm.
Have cleaned maf and throttle body more than once in last 6 months. Has new plugs, coil packs & k&n airfilter.
It's not throwing any codes on my cheap code reader. Any thoughts on where else I should be looking?
Thanks in advance.

Check for air leaks, check fuel pressure. If there are no air leaks, and the fuel pressure is fine, the fuel filter is clean, and the fuel pumps are good, get a new MAFs.

Check that all of the spark plug electrodes look the same. Any difference in electrode condition or color indicates a problem with that cylinder. It's a long shot here because the problem is intermittent, but it's easy to do.