CAT CODES = CAT FAILURE?

摘要

The catalytic converter is a simple device, really. No moving parts, no periodic adjustments needed. And it serves a vitally important purpose; that is, to make sure that what leaves the tailpipe is as clean as it can be. There is one weakness to the design, though. The exhaust gasses going into the cat have to be maintained in a very narrow lambda range. Feed gasses that are too lean (excess) or too rich (excess fuel) will both cause the cat's temperature to rise outside of the limits it can handle and can cause permanent damage to the chemical substrate contained within. And that just won't do. The Engine Control Module (ECM) is responsible for making sure that the feed gasses getting to the catalytic converter remain within those narrow boundaries. If things get out of control, Diagnostic Trouble Codes (DTCs) are set to alert the professional service technician that his or her help is required to protect the cat. Ignoring these warnings can lead to the meltdown or damage of the substrate, excessive emissions out of the tailpipe and the dreaded P0420/P0430 Catalyst Efficiency Below Threshold trouble code(s).