Does a CEL from cat delete affect performance?
Instructor
Joined: Sep 2008
Posts: 164
Likes: 42
From: Bozeman/Livingston MT Sometimes Texas
The purpose of the downstream (after cat) oxygen sensors is to measure cat efficiency and report that to the ECU. The ECU then adjusts fuel to keep the exhaust within the preprogrammed parameters. Although the removal of the catalytic converters may not directly set a trouble code the lack of ability to trim the fuel mixture very well might. On my Lingenfelter built C6Z they used high flow cats and this caused a DTC of inefficient catalytic converters. Using LS Edit or HP Tuners software we turned the downstream oxygen sensors off, making the ECU think all was OK. I guess what I am saying is to be safe reprogram the ECU.
