Heated O2 sensors?
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
I'm afraid I can't accurately answer the first part of your question as I don't know exactly when the switchover was made.
For GM you'll see essentially 3 types of O2 sensor, single wire, three wire, and four wire.
Single wires are non heated standard O2 sensors. Three wires work exactly the same and can directly be swapped for single wire sensors with a little wire splicing and will function just fine if you don't hook up the other two wires. The two extra wires are the heater, polarity doesn't matter, just connect one end to a fused / switched 12v source and the other to ground.
Four wire sensors have an additional wire that I believe goes back to the ECM for which I'm not completely sure about the purpose. If you're converting from non heated to heated it is easiest and cheapest to get 3 wire sensors.
For GM you'll see essentially 3 types of O2 sensor, single wire, three wire, and four wire.
Single wires are non heated standard O2 sensors. Three wires work exactly the same and can directly be swapped for single wire sensors with a little wire splicing and will function just fine if you don't hook up the other two wires. The two extra wires are the heater, polarity doesn't matter, just connect one end to a fused / switched 12v source and the other to ground.
Four wire sensors have an additional wire that I believe goes back to the ECM for which I'm not completely sure about the purpose. If you're converting from non heated to heated it is easiest and cheapest to get 3 wire sensors.
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Your 89 does not have a heated sensor. You do not need one if you run a stock exhaust in front, only those with headers may ever need it.
The difference is the extra wire to a switched 12V source that powers the heated element in the sensor, allowing it to read properly at 350C instead of the usual 600C.
The difference is the extra wire to a switched 12V source that powers the heated element in the sensor, allowing it to read properly at 350C instead of the usual 600C.
Drifting
Joined: Jul 2002
Posts: 1,273
Likes: 0
From: Olathe, KS USA
I know the '92 ZR1 has heated o2's (3wire) from the factory because that's the sensors I used when I upgraded to heated.
Here's a picture of my heated o2's and harness with factory weather pack connectors. Purple wire to ECM, one brown wire to "ignition on" 12v and other to ground.
http://www.digitalcorvettes.com/corv...nd_harness.JPG
Here's a picture of my heated o2's and harness with factory weather pack connectors. Purple wire to ECM, one brown wire to "ignition on" 12v and other to ground.
http://www.digitalcorvettes.com/corv...nd_harness.JPG
Thread Starter
Melting Slicks
Joined: Oct 2004
Posts: 2,283
Likes: 0
From: Leeds Alabama
So your ZR1 came from the factory with heated O2's, but your say you UPGRADED to heated O2's..I 'm not sure I understand. Thanks for the picture, as they say a picture is worth a thousand words. If you know, or others know which C4's cars ZR1,L98,LT1,LT4 model years came with what, I would appreciate the knowledge ,mainly for my personal C4 repair notebook.
Thanks!
Thanks!
Originally Posted by C4Crazy787
I know the '92 ZR1 has heated o2's (3wire) from the factory because that's the sensors I used when I upgraded to heated.
Here's a picture of my heated o2's and harness with factory weather pack connectors. Purple wire to ECM, one brown wire to "ignition on" 12v and other to ground.
http://www.digitalcorvettes.com/corv...nd_harness.JPG
Here's a picture of my heated o2's and harness with factory weather pack connectors. Purple wire to ECM, one brown wire to "ignition on" 12v and other to ground.
http://www.digitalcorvettes.com/corv...nd_harness.JPG
Drifting
Joined: Jul 2002
Posts: 1,273
Likes: 0
From: Olathe, KS USA
Originally Posted by corvette1989bham
So your ZR1 came from the factory with heated O2's, but your say you UPGRADED to heated O2's..I 'm not sure I understand. Thanks for the picture, as they say a picture is worth a thousand words. If you know, or others know which C4's cars ZR1,L98,LT1,LT4 model years came with what, I would appreciate the knowledge ,mainly for my personal C4 repair notebook.
Thanks!
Thanks!
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Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
I recently came across a long over-looked point in the Corvette Shop Manual about Open Loop/Closed Loop operation.
Manual says that the system may drop out of Closed Loop at Idle when the 02 cools off too much.
Seems that GM knew about that tendency way back at square one; something we with headers tended to think was unique to that mod.
If I come across the page number again, I'll post it.
Jake
Manual says that the system may drop out of Closed Loop at Idle when the 02 cools off too much.
Seems that GM knew about that tendency way back at square one; something we with headers tended to think was unique to that mod.
If I come across the page number again, I'll post it.
Jake