Can a bad EGR valve cause P0420?
Can a bad EGR valve cause P0420? My code turned out to be a bad egr valve. 99% of the time, a P0420 means you need to replace the deficient converter. O2 sensor failure *will not* cause the P0420 to set, but rather will give sensor failure codes. What causes the P0420 code on a Chrysler Town and Country? The P0420 code in a Chrysler Town and Country will often be thrown one of your oxygen sensors are not functioning properly. Typically, the code will be triggered by the upstream oxygen sensor (before the converter). There aren’t usually any drivability...