TWC efficiency?

[gtg737m]

Hello everyone,
I have a 1997 960 wagon and during the weekend I got the following code: PO422 Main Cat Efficiency Low Bank #1. Does anyone know what does this mean? What does TWC efficiency mean? I bouth this car a month ago, it was running great until I got the check engine light on. I've noticed that when I press on the fuel pedal when the car is in neutral the car makes a strange noise as if it had a vacuum leak. Any ideas? I don't want to start changing parts without really knowing what's the source of the problem. Thanks.

[petershen1984]

2001 Volvo V70 2.4T, 51300miles.

I am 9 days (!) shy of my limited warranty ending on a used Volvo V70, and the check engine light popped up...

Midas guys said that the warning was a PO422...the Main Cat Efficiency Low Bank #1.

I am planning on going to the shore this weekend (100+miles)...is it stupid to run the car for an extended period? I read somewhere about an EMC buildup (snicker as you like, I admitted I am carclueless).

The dealership said it could get to it next Thursday (two days before my warranty ends)...if the warranty expires how much am I looking out-of-pocket. If it is just as the warning said (a PO422), Volvo said it would be $385, if the whole catalyst converter goes it is covered by the Federal Warranty, what other potential problems could it be?
pompous pugs

bad front or rear o2 sensors or a bad catalytic converter.
tbaxleyjr

if you replace the cat and still get the code it coulda been bad o2 sensors, or the wiring to the sensors are broken or shorting out
BanffAutoSpa_ap