This Preliminary Information communication provides information to the technician about vehicles that may have Malfunction Indicator Lamp on. Technician may find Diagnostic Trouble Code P0420, P24A0 and or P2463. Technician should follow published Service Information diagnostics for the Diagnostic Trouble Codes that are set. If the diagnostic leads to diagnosis or replacement of the Q57 Indirect Exhaust After-treatment Fuel Injector, document all of your test results. If Diagnostic Trouble Codes P0420, P24A0 and/or P2463 are found, inspect the inlet and outlet of the Diesel Oxidation Catalyst for signs of damage, if damage is found replace the Diesel Oxidation Catalyst.