I got the P0420 diag. code and was reading up on it in varoius places but can't seam to find what the "Bank 1" means? Doe I need to replace left/right front/back catalyst converters??

Thanks in advance!

 

Probably more likely one of the o2 sensors.

 

Uh, no, P0420 refers to catalyst efficiency. If you watch the data on the cat monitor on a vehicle with a P0420 you will see the sensor works just fine, but switches must too fast. When these sensors go bad they tend to stick lean or not work at all.

 

Bank 1 is the side of the engine with cylinder #1, on an Expedition this would be the passenger side of vehicle, AKA the right.

 

Ok I guess I will start with the sensors, gotta be cheaper tha a cat. Is there something online I could look at for the location, like a microfisch. Sorry im really into working on bikes and don't know much about newer trucks.

 

You can do whatever you wish, but I think sensors would be a waste of money. The P0420, as I mentioned, does not point to a sensor but to the effectiveness of the catalyst.

 

As Btexpress said, replacing the sensor will never fix that code. It means just what he said, cat effeciency, not sensor slow to respond or nor working. It means it is switching just like the O2 sensor just ahead of the cat, meaning, nothing is going on in the cat. Therefore the only repair is replace the cat, or in some instances, reprogram the PCM to ignore that code. [sm=mail.gif]