I have been having a CEL pop up now and then(maybe once a month, comes on for a few days, then goes away). No difference in drivability/fuel economy, Autozone pulled code P0430 or something, can't remember.
'01 Escape XLT V6 on S100
CDT Audio/Ascendant Audio/Rockford/JBL/Knukonceptz setup
'00 SE Sport ATX