Hi all. Ihope you can help me with this problem I'm having. I have a 2002 T&C 3.8L With 101,300 miles. The check engine light came on and is reading "Catalyst System Efficiency Below Threshold (Bank 1)."I just performed a tune up at 100,000 replacing Plugs to Bosch Platinum 2and wires. It was running rich prior to the tune up and is still continuing to do so. I have noticed a large decrease in fuel efficiency. Soon after theerror itstarted tochug and run like crap.I am not sure if this code has to do with theo2 sensors or the catalytic converter.Anyideas would be helpful. Thanks!

 

need new converters.

 

Thanks for the help i will then replace it.