I have a 2009 gmc acadia with a troubleshooting code of p0420. The engine also suffers from a severe hesitatation upon rapid acceleration. Does this mean the cat is finished?

The fuel filter for the 2009 Acadia is built into the fuel pump. To replace it, the pump will have to be replaced.

wow no year car told. now that is a Hard row to hoe.. 2007 to NOW.
no engine told and cats are designed for engine and smog ,in one countries laws.
reset the all DTC errors via button on scan tool;
then drive see if P0420 comes back, first
not buy $400 cat on a whim./
I roll the dice, see 10, 2010
and answer. and LY7 engine V6 (there are others)

DTC P0420: Catalyst System Low Efficiency Bank 1
DTC P0430: Catalyst System Low Efficiency Bank 2


bank 1 means , that bank that contains cylinder #1
where is cylinder #1 it on all V engines, that cylinder that is MOST forward.
all cyl 1 are offset front

never post about cars and no year or engine told or post #8th digit of VIN this is engine code, so answer and be correct. (USA answer me only)

You will have 2. One of them is on the accelerator pedal, and the other is on the throttle body on the engine.

JUST BELOW THE OIL FILTER HOUSING ON THE FRONT OF THE ENGINE

Sounds like the magnetic clutch on the compressor may be defective or have an excessive air gap between the drive and driven plates (gap increases with engine temp)..

U073 is a communication code from one module to another to simply put it. Code U073 refers to a communication problem with the electronic brake control module ( Which controls ABS/Traction and stability ). I would suspect a loose connection/shorted wiring or even possible internal problem with the brake control module.If the issue occurs after hitting a bump, most likely a loose connection or the wiring rubbing somewhere causing a short from the brake control module.

Reverse sensor is bad or transmission in reverse is locked up.

I would go to what we use to call a junk yard.

Try this YouTube video:-
2009 GMC Acadia spark plug replacement

HAVE VECHICLE CODE SCANNED.YOU HAVE PROBLEM THE THE EMISSIONS AND ENGINE EVAPORATIVE CONTROL SYSTEMS.