Has anyone had to track down a P0422 - Main Catalyst Below Threshold, Bank 1
I am wondering if the catalytic convertor has gone bad or if the O2 sensor is having problems. The front O2 sensor was replaced about 6 months ago with a Bosch Universal from Autozone but the rear O2 sensor is the Volvo original from the factory. It has 123,000 miles and has been on the road for 6.5 years. I may just replace the rear O2 sensor with a universal so see if it solves the problem, but I was just wondering if anyone else had tracked this down and what the problem ended up being. Thanks in advance for any help. - David