To begin with, disconnect the battery so as to perform maintenance on the EGR system components. To install a new O-ring during installation, unplug the electrical connector from the EVP sensor, remove the mounting bolts, and then detach the sensor. Disconnecting the battery is required for EGRC or EGRV Solenoid(s). They can be found on firewall, you will need to unplug the electrical connector, label and detach vacuum hoses, and remove the solenoid if it is held by bracket screws. EVR solenoid requires removing the solenoid, unplugging the sensor harness electrical connector and vacuum hose, and detaching the battery cable. Detach the vacuum line and mounting bolts after unplugging the electrical connector from EGR valve position sensor of the EGR valve. The valve should be removed after taking out the threaded fitting for the external exhaust supply tube (if present), unscrewing the mounting bolting, and removing a vacuum line. The gasket should also be replaced. When substituting an EGR valve without a position sensor; one can transfer the old one to fit with a new O-ring. Disconnect the battery before dealing with TAB/AIRB or TAD/AIRD solenoid(s) on the firewall then unplug the electrical connector from the solenoids located there then mark before removal of their vacuum hoses and solenoid/bracket screws. Labeling and disconnecting hoses are done when replacing faulty components in air pump and control valves on MTA systems before reattaching hoses.
