Lincoln LS

It reads on my can-bus scanner: P0430, catalyst system efficiency below threshold. I took it to the ford dealer, and they put it on there machine to test it out ( it was not missing at that time when you step on it). They checked it out and said the left (drivers) side converter was not working. I looked under the car and could tell it had been replaced with the stickers still in good shape. They told me it would not effect anything but the emissions test. Well at some point now it is missing ( cutting out ) when you get on it. What do you think???

You don’t need to start another thread. Your answers are in the FIRST thread you started, “Catalytic Converters”…

First timer screw up.