oxygen Sensor Placement?

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Nov 3, 2006 | 06:13 PM

Steel Breeze

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Burning Brakes

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From: Richfield Utah

*oxygen Sensor Placement?*

I have an 88 L-98. I am looking at some headers. These headers have no O2 provision. I would have to weld in a bung. These are long tube headers. Does it matter where it is put ie. in a tube, in the collector area, where? Thanks...

Nov 3, 2006 | 06:29 PM

CFI-EFI

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From: The Top of Utah

If you put the bung into an individual tube the O2 will only sample that cylinder for the purposes of adjusting the A/F mixture. That isn't a serious flaw. Hooker does it. But it can frustrate trouble shooting some problems. Because the O2 has to be at approx 600° in order to for the system to go into closed loop, it is desirable to have the O2 as close to the engine as the headers will allow. If the O2 won't stay hot and in closed loop, idle seems to be the problem time, a heated O2 may be necessary.

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Nov 3, 2006 | 06:36 PM

lefoy84

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I put a heated O2 in the collector. Works fine. An unheated one probably would not.

Nov 3, 2006 | 06:57 PM

Steel Breeze

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Burning Brakes

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From: Richfield Utah

What a great bunch of advice. I would not have guessed that. I didn't relize there were heated O2 sensors. 600* ummmm, how do the heated units hook up, are they powered off the battery? Thanks

Nov 3, 2006 | 08:02 PM

CFI-EFI

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I would try your stock, unheated, O2 first to see if it stays in closed loop before you invest in a heated O2. Your stock O2 has a 1 wire hook up. The heated O2 has 3 and sometimes 4 wires. One wire connects to the ECM, like the old set up. One wire connects to a switched 12 volt source, and one for ground. I believe the best power source is through a relay. I don't have one so my information is a little generic. I'm sure you can hook it up either way. *I* like the idea of a relay. There have been multiple threads on the powering of the O2 heater. Try a search.

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Nov 3, 2006 | 09:31 PM

lefoy84

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Quote:

Originally Posted by Steel Breeze

What a great bunch of advice. I would not have guessed that. I didn't relize there were heated O2 sensors. 600* ummmm, how do the heated units hook up, are they powered off the battery? Thanks

Mine had three wires. One to hook up to the original 02 input to the ecm, a ground, and a 12v lead that is connected to a convenient switched source. Hardest part is installing the bung. I didn't use a relay as they don't seem to draw alot of power, but it would be a good precaution. I used the Bat lead to the distributor on my 86. It was convenient because I was reinstalling the engine and added the 12v wire to the harness that feeds the distributor.

Last edited by lefoy84; Nov 3, 2006 at 09:36 PM.