× Auto Repair Pros Member Benefits TechHelp Knowledge Base Forums Resources My iATN Marketplace Chat Pricing About Us Join Industry Sponsors Video Members Only Repair Shops Auto Pro Careers Auto Pro Reviews
Join Now
International Automotive Technicians Network
Re: Catalyst Monitor - P0420 Catalyst Efficiency below threshold.
Posted to Technical Discussion Forum on 8/25/2001 2 Replies

Hi Scott,

There is a TSB on these and it covers replacing/reprogramming the PCM and replacing the Cataylst. Been there, done that.

Here was my version of your post:

1997 Mazda 626 P0421 - sponsorship finds the answer!

and the

dual O2 sensor waveform"... Login to read more.

Files Referenced:

thumbnail

2 Replies Received (View Replies)