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Oxygen Sensor Location (O2 Sensor)


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For easy reference and so we don't need to go searching for this all the time, I thought a topic with the O2 Sensor Location on the Northstar be helpful. Mike

Bank 1 Sensor 1 - right bank (rear) manifold

Bank 1 Sensor 2 - pre-cat

Bank 1 Sensor 3 - aft-cat

Bank 2 Sensor 1 - left bank (front) manifold

Always warm the engine up before trying to remove them

If you remove one and plan to reinstall, use anti-seize on the threads

There is an O2 sensor socket with a slit in it to accomodate the wire but we have seen crow's foot used to remove them

NEVER run your engine for a long time with an O2 sensor code current, you can damage your CAT. This is because the system stays in OPEN LOOP and the engine runs RICH, overheating the CAT.

There is a school of thought that believes that O2 sensors become slow to respond long before they set a code and that they should be replaced every few years to maintain engine performance.

The O2 sensor's job is to balance to air/fuel ratio to strive for a stoichiometic mixture of about 14.7:1. see this >>http://members.surfb...rs/O2sensor.htm

I like these tech papers from autotap.com on O2 sensors for additional information and diagnosis. I have an Autotap scanner


Feel free to add any TIPS. O2 sensor questions SHOULD be placed in a NEW THREAD, this is only a reference thread

Can this be 'pinned' in a place where it is easily accessible but still searchable?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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