Oxygen Sensor on '85 Chevy??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crawdad · 04-10-2006, 08:17 PM

I was under my truck today looking for it and couldn't find one. It appears there never was one either, as I couldn't find a connector anywhere in the exhaust pipe. Did the '85's have the oxygen sensor? I don't think I have a computer in my truck either, just that thing that advances the timing (that has been disconnected and bypassed. In fact, the only emissions equipment I can find are the air pump with only one fitting to the exhaust manifold on each side and the EGR valve. Was there anything else on this year model?

beaterC10 · 04-10-2006, 08:41 PM

You wont have an oxygen sensor unless you have tbi. You might also have a vacuum swith on the thermostat neck, possibly a computer controlled carb, pcv valve, thermostatic valve in the air cleaner inlet, and a vent between the air cleaner and valve cover.

Chevrolet4x4s · 04-10-2006, 09:08 PM

My 85 no computer(of corse it was originally a diesel)
Shane

crawdad · 04-10-2006, 09:11 PM

Quote:

Originally Posted by beaterC10

You wont have an oxygen sensor unless you have tbi. You might also have a vacuum swith on the thermostat neck, possibly a computer controlled carb, pcv valve, thermostatic valve in the air cleaner inlet, and a vent between the air cleaner and valve cover.

I think I've got just about everything you said, however, what is a computer controlled carb? I know there is something installed on top/front of the carb with two wires coming out of it. If it's computer controlled, where is the computer?

Thanks for your help.

gchemist · 04-10-2006, 09:12 PM

California models had oxygen sensors way back to at least 83 with a carb. My factory manual shows wiring for it.

Slonaker · 04-10-2006, 09:33 PM

I don't know about the CA models, but the others did not have a computer controlled carb. The wires that go to the carb control the dual capacity acelerator pump. AFAIK, it is activated by a temp switch on the thermostat housing.

Slonaker

crawdad · 04-10-2006, 09:46 PM

Quote:

Originally Posted by Slonaker

I don't know about the CA models, but the others did not have a computer controlled carb. The wires that go to the carb control the dual capacity acelerator pump. AFAIK, it is activated by a temp switch on the thermostat housing.Slonaker

Yep, without running outside to verify, I believe that is exactly where that wire runs to.

crawdad · 04-10-2006, 09:51 PM

All of this is really leading me to my next question. I know that the catalytic converter is clogged up on my truck. Since we don't have the smog inspections where I live in GA, is there any good reason why I shouldn't just yank the air pump out, and run headers with dual exhaust? I'm sure it would be beneficial to my gas mileage.

Slonaker · 04-10-2006, 11:44 PM

No reason why you shouldn't...

Slonaker

beaterC10 · 04-11-2006, 06:13 AM

The only problem might be finding a muffler shop to do the work. We don't have smog in Indy and some shops still wont touch a truck that has headers. I got a quote a few weeks back for my 86. The shop wanted $500 for duals from the headers back with mufflers and cats.

bejay · 04-11-2006, 06:46 AM

do you have a vehicle inspection at all?
if so you might want to check what all is checked on the vehicle before taking a bunch of stuff off.

crawdad · 04-11-2006, 10:36 AM

Quote:

Originally Posted by bejay

do you have a vehicle inspection at all?
if so you might want to check what all is checked on the vehicle before taking a bunch of stuff off.

Nah, no inspection at all. They do have smog inspections in Atlanta, I believe, but we don't claim Atlanta as part of GA anymore.

Slonaker · 04-11-2006, 11:14 AM

Save anything you take off. You never know when smog inspections will be brought in.

Slonaker

Prerunner1982 · 04-11-2006, 02:56 PM

the only computer it might have is for the ESC (electronic spark control).. there is an article on www.73-87.com that shows how to remove it.

Chevrolet4x4s · 04-22-2006, 06:53 PM

AAAH WHAT GREAT WEBSITES showing how to de-electronicalize(a word in my mind

) vehicles
Shane

Edit:YEEHAW post 427

04-10-2006, 08:17 PM	#1
crawdad Senior Member Join Date: Sep 2004 Location: Georgia Posts: 614	Oxygen Sensor on '85 Chevy??? I was under my truck today looking for it and couldn't find one. It appears there never was one either, as I couldn't find a connector anywhere in the exhaust pipe. Did the '85's have the oxygen sensor? I don't think I have a computer in my truck either, just that thing that advances the timing (that has been disconnected and bypassed. In fact, the only emissions equipment I can find are the air pump with only one fitting to the exhaust manifold on each side and the EGR valve. Was there anything else on this year model? __________________ 2012 Silverado LT 1500, 5.3, 6 speed auto '86 SWB C-10 Silverado

04-10-2006, 08:41 PM	#2
beaterC10 Senior Member Join Date: Jul 2003 Location: Indianapolis, IN Posts: 1,277	Re: Oxygen Sensor on '85 Chevy??? You wont have an oxygen sensor unless you have tbi. You might also have a vacuum swith on the thermostat neck, possibly a computer controlled carb, pcv valve, thermostatic valve in the air cleaner inlet, and a vent between the air cleaner and valve cover.

04-10-2006, 09:08 PM	#3
Chevrolet4x4s Registered User Join Date: Nov 2005 Location: WV Posts: 227	Re: Oxygen Sensor on '85 Chevy??? My 85 no computer(of corse it was originally a diesel) Shane __________________ 1993 K1500 350 5 speed 1985 K10 Silverado Vortec 406 5 speed (in body shop) "I been drivin' this '85 pickup truck Them buddies of mine call it a bucket of rust She's a little beat up but she still runs like the wind Yeah, kinda like me I been banged and bruisedBeen around the block a time or two But I'm runnin' like new goin' places I never been No, I ain't broke I'm just broken in" 1963 Dodge Townwagon(its amazng what 30 years and zero miles will do to a vehicle ) Member#20327

04-10-2006, 09:12 PM	#5
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: Oxygen Sensor on '85 Chevy??? California models had oxygen sensors way back to at least 83 with a carb. My factory manual shows wiring for it.

04-10-2006, 09:33 PM	#6
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	Re: Oxygen Sensor on '85 Chevy??? I don't know about the CA models, but the others did not have a computer controlled carb. The wires that go to the carb control the dual capacity acelerator pump. AFAIK, it is activated by a temp switch on the thermostat housing. Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

04-10-2006, 09:51 PM	#8
crawdad Senior Member Join Date: Sep 2004 Location: Georgia Posts: 614	Re: Oxygen Sensor on '85 Chevy??? All of this is really leading me to my next question. I know that the catalytic converter is clogged up on my truck. Since we don't have the smog inspections where I live in GA, is there any good reason why I shouldn't just yank the air pump out, and run headers with dual exhaust? I'm sure it would be beneficial to my gas mileage. __________________ 2012 Silverado LT 1500, 5.3, 6 speed auto '86 SWB C-10 Silverado

04-10-2006, 11:44 PM	#9
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	Re: Oxygen Sensor on '85 Chevy??? No reason why you shouldn't... Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

04-11-2006, 06:13 AM	#10
beaterC10 Senior Member Join Date: Jul 2003 Location: Indianapolis, IN Posts: 1,277	Re: Oxygen Sensor on '85 Chevy??? The only problem might be finding a muffler shop to do the work. We don't have smog in Indy and some shops still wont touch a truck that has headers. I got a quote a few weeks back for my 86. The shop wanted $500 for duals from the headers back with mufflers and cats.

04-11-2006, 06:46 AM	#11
bejay Registered User Join Date: Aug 2005 Location: missouri Posts: 136	Re: Oxygen Sensor on '85 Chevy??? do you have a vehicle inspection at all? if so you might want to check what all is checked on the vehicle before taking a bunch of stuff off.

04-11-2006, 11:14 AM	#13
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	Re: Oxygen Sensor on '85 Chevy??? Save anything you take off. You never know when smog inspections will be brought in. Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

04-11-2006, 02:56 PM	#14
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	Re: Oxygen Sensor on '85 Chevy??? the only computer it might have is for the ESC (electronic spark control).. there is an article on www.73-87.com that shows how to remove it. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

04-22-2006, 06:53 PM	#15
Chevrolet4x4s Registered User Join Date: Nov 2005 Location: WV Posts: 227	Re: Oxygen Sensor on '85 Chevy??? AAAH WHAT GREAT WEBSITES showing how to de-electronicalize(a word in my mind ) vehicles Shane Edit:YEEHAW post 427 __________________ 1993 K1500 350 5 speed 1985 K10 Silverado Vortec 406 5 speed (in body shop) "I been drivin' this '85 pickup truck Them buddies of mine call it a bucket of rust She's a little beat up but she still runs like the wind Yeah, kinda like me I been banged and bruisedBeen around the block a time or two But I'm runnin' like new goin' places I never been No, I ain't broke I'm just broken in" 1963 Dodge Townwagon(its amazng what 30 years and zero miles will do to a vehicle ) Member#20327 Last edited by Chevrolet4x4s; 04-22-2006 at 06:54 PM.

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