What were the 3 quotes you received?I have had a P0420 CEL in my Versa for a while, also noticed a lack of power. Fairly sure it's a bad catalytic converter.
Realistically, how long can I just leave it be until the car dies? I've been driving around with this CEL on for about a year now. The cost of buying and installing a new cat is more than the car is worth and we don't have emissions testing here.
2009 Versa, base model, 215k kilometres. I would love to repair it properly but given how old it is, it doesn't really make economic sense.