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2nd Gen Ram Tech1994-2001 Rams: This section is for TECHNICAL discussions only, that involve the 1994 through 2001 Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
Hey, i have a PO420 code, i know what it is but I dont know where it is located on the exhaust. Catalyst System Efficiency Below Threshold (Bank 1). Any help would be great to where it is located.
Jamie, is your cat hollowed out by any chance? My cat is gutted and I occasionally get the P0420 code because of it. If I don't clear it myself it usually goes away after a while. If your cat isn't gutted, it may be getting plugged. 90% of the time it's the cat at fault, not the O2 sensor.
My code doesnt go away unless i clear it and I am trying to figure out where behind the cat converter is the bad o2 sensor since it is the Catalyst System Efficiency Below Threshold (Bank 1).