I recently installed a header and "high flow" cat converter in my 98 civic EX and now I am getting a code P0420 because this "high flow" cat doesn't work all that well. How can I keep the light off and keep the new converter??? I was thinking of disconnecting just the signal return wire treminal (harness side) from the cat monitor sensor(down stream o2). Will the ECM be satisfied with a constant signal or 0 Volts or is it going to need to see a bias rich condition after the cat??? Is there something else that I should do in order to solve this problem???

 

just put a 02 sensor simulator on the second sensor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by douspray &raquo;</TD></TR><TR><TD CLASS="quote">just put a 02 sensor simulator on the second sensor.</TD></TR></TABLE>
that would be the best way to get rid of the CEL.