Troubleshooter's Forum
Hey,
I'm trying to diagnose a P0421 on my '03 Durango 4.7L (220k miles). I got the truck up to operating temps and hooked up my scan tool (Launch Gear Scan Plus). The voltage wave forms for the B1S1 & B2S1 O2 sensors are switching between 0.1 & 0.9 volts as expected. The B2S2 O2 sensor is fairly...