Need help with rough idle

[cx9 2008]

I have a frustrating rough idle in my 2008 cx9 i have almost changed everything and still nothing changed i changed coils, plugs, injectors, fuel rail, wiring harness, Ecm, fuel filters, intake manifold, brake booster, throttle body, done smoke test, both upper o2 sensors, deleted cats, alternator, maf sensor, cam sensors, crank sensor, knock sensors, coolant temp sensor, oil pressure sensor, fuel pressure regulator, rebuilt the whole engine with factory parts.

Can any body help me because im almost gonna give up but not after everything i changed, and by the way no codes show up!

 

[erhayes]

Low quality or old fuel can cause your issues. A 20 miles highway run at speed with several 5 second WOT runs to clear combustion chamber crud.

 

[cx9 2008]

Low quality or old fuel can cause your issues. A 20 miles highway run at speed with several 5 second WOT runs to clear combustion chamber crud.

I rebuilt the whole engine and of course cleaned the pistons. Dont worry my engine is always screaming at 6500 rpm!!!!