JUST USED MY CAR MD ON A FRIEND'S VEHICLE. SHE HAS A 2004 ACURA MDX. SHE HAS CODES: PO420, PO457, P2237 NOSUP. PLEASE EXPLAIN

Hi:

You  may want to check your vacuum lines and wiring under the hood. Check for signs of rodents trying to nest and chewed up wiring and hoses. Part of your codes show you may have a vacuum leak, which in turn, can cause the other code.

Check the front oxygen sensors are plugged in and good wiring.(ones in exhaust manifolds) . Also check to see gas cap is tight and seals correctly along with any(2 i believe) green threaded caps in ,around engine compartment. On a plastic hose near fitrewall or top of engine.  The 400 codes are Evap. Codes. This system needs to be airtight from solenoid to and including fuel tank.  2237 is seeing that reading  at sensor is high which can be a vacum leak(the caps) or wiring/connection at sensor 1.  Make sure all 4 wire are intact.