have a 2003 town n country van check engine light came on, went to the parts store to get it read. It said : catalyst system efficiency below threshold ( Bank 1 ) what does that mean in simple terms ?

Also I would like to purchase one ot those engine scan tools, I don't need a top of the line professional grade one but don't want some chaep junk either, is there a good brand and model anyone would suggest, my brother in law has an auto x-ray and says its better than the one the parts store lets you use, I don't know, any suggestions ? Thanks.

It means you need a new converter. You cannot regenerate the converter once it's efficiency drops below a certain minimum conversion percentage.

It had a new converter about a year ago, at that time the code reader said converter this time not. And sugestions on a brand of scanner to get ?