1980 GMC G3500 Catalytic Converters

By definition, P0420 code reads “bank one Catalyst Efficiency low”.  A vehicle displaying this code indicates that something is causing the converter to operate out of specification. Further diagnostics and/or inspection is required before determining the part is defective.

You can start your search here where you’ll provide your vehicle information, including year, make, model and sub-model. If you have further questions, please contact our technical department here.

EFN stands for “Engine Family Number”. It is found on the emissions control tag underneath the hood of your vehicle. This number is needed to ensure the correct part is provided for your California compliant vehicle. It is illegal to equip a registered California or New York vehicle with a federal and/or non-California compliant part. For more information, please visit the following page.

Standard grade products are manufactured with the required precious metals to be compliant with a properly tuned and operating vehicle.

HM and OEM grade products are designed to function with the Engine Family Number specific designs calling for more precious metals to be used. HM and OEM grades ensure both tailpipe and engine management system compliance is adhered to, while keeping the “check engine light” off. In addition, the extra loading of precious metals will allow for proper engine management interaction and provide additional emissions conversion for vehicles which may not be running at 100%.

Both options will perform equally. Direct-fit parts are easier to install as they are designed to be bolt-on with zero welding required. Universal parts will require professional installation that may include cutting and welding in order to fit. To check the available parts for your vehicle, please start yoursearch here. If you have additional questions, you can contact us here.

No, it will not. It is illegal for a dealer, installer or manufacturer to deny you the OE warranty because you’ve changed the exhaust system. Please refer to the Magnuson Moss Warranty Act of 1975, 15 USC, 2302 and Clean Air Act 42 of USA code 7541 for more information.