Can you advise what the issue could be based on the codes I get below.

Question

I drive a 2008 Acura MDX. A Check Emissions light comes on and when I checked the codes I get the following 4 codes in order: P2413, P0404, P0134, P2251. Any ideas what it could be? I previously replaced an oxygen sensor about a year ago.

Answer 1

P2413 EGR system malfunction

P404 EGR control circuit range performance problem

P0134 Rear A/F (airflow sensor) bank1 sensor 1 heater system malfunction

P2251 Rear A/F (airflow sensor) VS circuit high

Replace the EGR if the valve stick open you can get these code. P0134 is a result of a open EGR , P2251 is a result of P0134..