Switching from a 3 wire to a 4 wire(heated) O2 sensor - The 1947 - Present Chevrolet & GMC Truck Message Board Network

HuggerCST · 11-18-2007, 11:55 AM

I recently converted my '85 GMC to TBI and installed headers. It runs terrible in cool weather, and the original oxygen sensor is mounted in the bottom of the header. I've been told that it needs a 4 wire heated sensor, but I don't know what to ask for. Is there a kit to do this, or will any 4 wire sensor work? I also need to know how to wire it. Has anyone done this before?

G35MIKE · 11-18-2007, 11:59 AM

I was under the impression that 4 wire heated o2 sensors were used in obdII cars/trucks to monitor the Cat converter, and was placed after the cat?

swb85 · 11-18-2007, 12:16 PM

Quote:

Originally Posted by G35MIKE

I was under the impression that 4 wire heated o2 sensors were used in obdII cars/trucks to monitor the Cat converter, and was placed after the cat?

They are also used pre-cat to control fueling.

c502 · 11-19-2007, 07:18 AM

I did it to my 84 454 when I TBI's it. However I think I went to a 3 wire from a 2 wire. Used a GM Part number 25312185.

11-18-2007, 11:55 AM	#1
HuggerCST Registered User Join Date: Jul 2001 Location: North Louisiana Posts: 4,501	Switching from a 3 wire to a 4 wire(heated) O2 sensor I recently converted my '85 GMC to TBI and installed headers. It runs terrible in cool weather, and the original oxygen sensor is mounted in the bottom of the header. I've been told that it needs a 4 wire heated sensor, but I don't know what to ask for. Is there a kit to do this, or will any 4 wire sensor work? I also need to know how to wire it. Has anyone done this before? __________________ Wynne 70 CST short fleet Hugger orange & white, 350/350, ps, pb, air, tilt, tach/vac/speedwarning, original buckets, AM/FM, oak bed floor, shoulder belts, 3.5"/5.5" drop, 20" American Racing VN425s. Build thread 53 Chevy shortbed 69 Camaro Click here to subscribe Chevy GMC International Truck Club Louisiana Charter Member http://www.louisianaclassictruckclub.com

11-18-2007, 11:59 AM	#2
G35MIKE Registered User Join Date: Oct 2005 Location: lakewood Posts: 79	Re: Switching from a 3 wire to a 4 wire(heated) O2 sensor I was under the impression that 4 wire heated o2 sensors were used in obdII cars/trucks to monitor the Cat converter, and was placed after the cat? __________________ g35s (areo,premium,navi) 67' fleetside Last edited by G35MIKE; 11-18-2007 at 12:00 PM.

11-19-2007, 07:18 AM	#4
c502 Registered User Join Date: Sep 2004 Location: Elizabeth, Colorado Posts: 20	Re: Switching from a 3 wire to a 4 wire(heated) O2 sensor I did it to my 84 454 when I TBI's it. However I think I went to a 3 wire from a 2 wire. Used a GM Part number 25312185. __________________ big blocks=life



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.