o2 sensor location

[Joe dinubilo]

I have a 1982 chevy c 10 truck with a 305 engine that Im working on for my son. took it to get smogged and they told me that the o2 sensor is missing, can someone tell me where the o2 sensor should be located. I did find a wire hanging on the back of the transmission bellhousing,its a single wire connector. Is that possibly the wire that goes to the non existent 02 sensor.Im in California so no smog means no registration.

[bd]

The O₂ sensor threads into a hole cast into the left exhaust manifold, directly above the headpipe flange.  The ECM harness connects to the sensor via a single wire Weatherpack connector.

[Joe dinubilo]

Thanks for the info. Someone must have changed out the exhaust manifold on this truck because there is no place for a o2sensor on the exhaust manifold.

[bd]

Take a look at this manifold.  Note the pipe plug right above the flange.

[roundhouse]

I thought they didn't get TBI until 87 ??

So why would an 82 have a oxy sensor ?

[bd]

I thought they didn't get TBI until 87 ??

So why would an 82 have a oxy sensor ?

(Light goes on)  You're right!  Some of the El Caminos had it in 1982, but feedback carburetion didn't go into production on trucks until 1983 or 1984.  The '82 C10 shouldn't have feedback emissions.

Joe, what color is the wire you described, hanging down beside the transmission?

[78BIG-TEN]

I was thinking the same thing but wasn't sure about California versions.Here in Texas I cant recall ever seeing a truck with feedback carb,only tbi in 87

[bd]

In California, beginning about 1980, we rarely saw anything other than feedback systems.  They gradually encroached until nothing "traditional" remained.  Trucks lagged behind cars, which included El Caminos & Caballeros, but boasted feedback carburetors by 1983 or '84.  Those were years of discovery....

[Dan75k20]

I had an 81 regal with a feedback carb and a check engine light. I never heard or have seen an o2 sensor on a pre fuel injected vehicle

[roundhouse]

If all that's required is a visual inspection
Then I'd install a O2 sensor for them to see

You've had it tested ? 
It passes the tailpipe sniffer ?

You registering it for the first time in Cali?
Or was it registered before ?

[Joe dinubilo]

THE single wire hanging down on the bellhousing is a brown wire with a weather proof connector. The truck did pass the emission part of the smog check but not the visual. The smog results were considered TAMPER therefore no certificate was issued. This truck is new to my son and yes it had been registered in Ca.before. When my son purchased the truck it had not been registered since 2008 so he paid the back registration fees 500.00 but needs to get it smogged before they issue tags. The exhaust manifold does'nt have any provisions for a o2 sensor.

[bd]

Could the brown wire be dark purple?  Can you post a pic of the top of the carburetor and the 'brown wire?'

[VileZambonie]

What makes them think your truck has an Oxygen Sensor to begin with? Is your VECI label under the hood in tact? I'm thinking M4ME if its a 4bbl. Sounds like they need an oxygen sensor to detect how much oxygen they are wasting that the rest of us could be using.

[roundhouse]

I'd take it to a different station

But you Gota decide if it's easier to try and convince em it doesn't need one or just screw one in and plug thr wire  on

[Irish_Alley]

 back registration fees 500.00? WTH is this??? you have to pay for someone else taking the truck off the road?