Some Acura 2011-13 vehicles may turn on the check engine light and store EVAP trouble code P0455 and/or P0456 in PCM memory.
Before you get into in-depth diagnosis, check the gas cap; It may be loose or have a stick-slip feel when tightened, which indicates a bad seal at the fuel pipe flange. The material that the cap gasket is made of is what causes the EVAP leak.
Installing an updated gas cap with a different design gasket is the simple fix. Order part # 17670-SZN-A01 for ZDX models; or part # 17670-TRO-A11 for ILX, MDX, RDX, TL and TSX models. Before ordering the new cap, however, remove the existing cap and take a look at the color of the gasket. If the gasket is brown, the new cap is already installed and this information doesn't apply. In that case continue troubleshooting until the EVAP system leak is found.
Vehicles that are prone to the condition and can benefit from the updated gas cap are 2011-13 TSX models; 2012-13 MDX, RDX, TL and ZDX models; and 2013 ILX models.
"Factory Fixes" is written by Jim DePalma, a 30-year veteran of the auto repair business who has served stints as a service manager, parts manager and ASE-certified technician. His column provides vehicle manufacturers' authentic factory technical service bulletins (TSBs) that have been condensed for easier reading. Mr. DePalma advises that techs always check with a dealer or repair information system for the latest revisions before starting to work on a vehicle. He can be reached via email at [email protected]