Edelbrock 3550 - Manual (Page 15)

15
Pro-Flo EFI Installation Instructions
©2005 Edelbrock Corporation
Brochure No. 63-0115 Rev. 10/05
The exhaust gas oxygen content is determined by the oxygen sensor. The sensor signals the ECU, which compensates when the air/fuel mixture
is either rich or lean.
NOTE: It is recommended that the O 2 sensor installation be performed by a professional muffler shop.
1. Double check header gaskets, replacing if necessary.
2. Drill a 1/2-inch to 9/16-inch hole in the passenger-side header collector reducer, as close to the header flange as possible. (1" to 3" away)
NOTE: Before drilling, make sure the O
2 sensor will be mounted horizontally and within reach of the harness connector. Check to ensure
adequate clearance for the sensor, taking into consideration engine movement.
3. Fit the provided fitting into the hole in the exhaust pipe and weld into place.
4. Once it has been welded into place, clean the threads in the center of the fitting. If your exhaust is coated tap bung threads to ensure a
good ground for the 0/2 sensor.
5. Thread the O
2
sensor into the fitting. A high-heat anti-seize compound is included and needs to be applied to the sensor threads.
NOTE: The O 2 sensor has 18mm x 1.25 spark plug threads.
6. Attach the O 2 sensor to the main system harness Connector J21. Refer to the MAIN SYSTEM HARNESS section of this manual.
NOTE: UNLEADED FUEL MUST BE USED ONCE THE O
2
SENSOR HAS BEEN INSTALLED.
COATED HEADERS: Use a digital OHM meter to measure the resistance between cylinder head bolt and the body of the installed 0/2
sensor. The reading should be less than 1 OHM. If it is higher, you need to provide a ground to the 0/2 sensor mount.
O
2
SENSOR INSTALLATION