Oop! Revised for the Zetec.
A good cheap way to test for a blocked exhaust is to remove the O2 sensors, in this order (and see if the performance improves). Uninstall Lower to determine if main cat is plugged, reinstall lower and then uninstall Upper to determine if precat is plugged. Battery needs to be disconnected before uninstalling and installing O2 sensors. Good luck.
Last edited by Tony2005; 10/23/05 03:56 AM.
