My 2003 Dodge Ram 1500 gives the below error could when tested? What needs to be replaced to fix the problem?
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
Dodge Ram 1500 Quad Cab 4X4 - 5.9 v8 Engine
have the same problem?
Monday, December 1st, 2008 AT 11:06 PM
Check cat for cracks ands discoloration due to heat.
Check for exhaust leaks. If all good then are both O2 OEM one could be slow to respond cvausing code.
Also any oil or antifreeze in exhaust will cause code.