I have an 05 chrysler town and country runs but won’t go higher than 2500 rpms I’ve replaced the cam shaft and crankshaft sensors drill out the cat replaced maf sensor and put in new plugs n wires and still doin it codes read p0016 and p0420 what will cause it to do this
P0016 usually indicates that the camshaft and crankshaft are mistimed, probably unlikely unless the timing chain was installed incorrectly.
Inspect the transmission flex plate, the crank sensor tone wheel is mounted on the flex plate, if the center of the flex plate cracks and the tone wheel moves out of position by a few degrees it will cause your symptom.
If you drilled out the cat, you will always get the P0420.
You are working on this car yourself, and basically just guessing at the fix, right?
Stop that. Drilling out the cat is illegal and potentially toxic to yourself and the cause of your P0420 code.
Since you changed the camshaft and are getting a P0016, I’d say you didn’t get it timed correctly.