XC70 2001 Catalyst efficiency low-bank Code P0422

[jamesstar9]

My volvo check engine light is on. I took the car up to Autozone for the free check engine light code read. The code that came up was P0422 Defintion "Catalytic efficiency low-bank"
Probable cause
1. Engine misfire or running condition.
2. Vacuum leak.
3. Engine oil leakage into exhaust-valve guide.

The engine starts fine and I notice no misfires. The engine oil level looks good and I change it every 3,000 miles so I don't think thats the cause. So I am not really sure where to start in troubleshooting the car if it is a vacuum leak or how do I test if the catalytic converter is bad any suggestions would be greatly appreciated.

[MadeInJapan]

Check for vacuum leaks with propane or even by spraying carb cleaner around suspected areas when the car is idling. If the car surges, you've found your leak(s).