Question: Oxygen sensor removed???

[Antz81]

Got my first vette a few weeks ago and started fixing it up. Once I replaced the lamp for the check engine light I noticed it was going on and off as I was driving.
after checking the codes (13, 23, 34) I began to have a look around.
34 is an easy one, the sensor most likely just needs to be connected to the carb again (not sure why this would have been left of.
when I began looking into the oxygen sensor problem I noticed something odd, I can find the plug for it on the wiring loom, but the sensor itself is MIA. From what I gather it should be on the exhaust pipe just below the header. The exhaust and headers have been changed, but not sure why the O2 sensor would have been left out. Any ideas on my best option from here???
should I just bridge the sensor out with a resistor so the ECM thinks it's ok, or am I better off getting a hoe drilled and tapped for it?

 

[redvett]

What M&Y? If it was a vehicle built for USA emissions you will need an O2 sensor, some exports didnt require it but e prom is different.

Got my first vette a few weeks ago and started fixing it up. Once I replaced the lamp for the check engine light I noticed it was going on and off as I was driving.
after checking the codes (13, 23, 34) I began to have a look around.
34 is an easy one, the sensor most likely just needs to be connected to the carb again (not sure why this would have been left of.
when I began looking into the oxygen sensor problem I noticed something odd, I can find the plug for it on the wiring loom, but the sensor itself is MIA. From what I gather it should be on the exhaust pipe just below the header. The exhaust and headers have been changed, but not sure why the O2 sensor would have been left out. Any ideas on my best option from here???
should I just bridge the sensor out with a resistor so the ECM thinks it's ok, or am I better off getting a hoe drilled and tapped for it?

 

[Antz81]

it's an 81, believe it was exported to japan. All of the wiring for the O2 sensor is there and with it bringing up the fault makes me think it should have one. The exhaust and headers have been replaced so its now true twin exhaust. if it did have an O2 sensor i'm guessing this is when it was removed.

 

[bill81vette]

1st Welcome to CAC!!!
enjoy!!!

you could drill and tap for another O2 sensor or just remove the lite bulb from the dash

Be sure to check out the L-81 registry and register your '81.

 

[Antz81]

Thanks, I think I'll go for the drill and tap option. I do want to get things going as they should.

 

[Midnight 99]

In an 81, the sensor would have been in the exhaust down pipe. When you say headers, do you mean the cast iron exhaust manifolds or do you mean long tube headers? If you have a set of headers on the car, that is the reason that you don't have an O2 sensor. The 81's were cross fire injection and did not have a carb. If you have a carb that's another change to the car from stock configuration. Unless you are trying to set the air fuel mixture, you really don't need the O2 sensor. Remove the bulb from the check engine light and call it good.

 

[Tommy Almond]

In an 81, the sensor would have been in the exhaust down pipe. When you say headers, do you mean the cast iron exhaust manifolds or do you mean long tube headers? If you have a set of headers on the car, that is the reason that you don't have an O2 sensor. The 81's were cross fire injection and did not have a carb. If you have a carb that's another change to the car from stock configuration. Unless you are trying to set the air fuel mixture, you really don't need the O2 sensor. Remove the bulb from the check engine light and call it good.

Correction here, the '81s had the q-jet carb and ECM controlled, the '82s was the first year of the cross fire.

 

[Hib Halverson]

Tommy Almond is spot on. 81s all had carburetors.

As for export cars not having O2 sensors, I'm not sure that's true, but if it is, the carb would not be electronically controlled, but since DTC13 is stored, we can assume that, up to now, the engine was run in open loop w/o the sensor and the previous owner just lived with the engine light on. Putting a sensor back in will improve fuel economy and decrease exhaust emissions but likely will not change the car's performance at high throttle openings.

You said the car has replacement manifolds and true dual exhaust.

Can you describe the exhaust manifolds?

 

[Antz81]

Tommy Almond is spot on. 81s all had carburetors.

You said the car has replacement manifolds and true dual exhaust.

Can you describe the exhaust manifolds?

Sure, defiantly not original. Has long pipes from each cylinder that work their way down to the bottom of the motor. From there they all change to be horizontal and join to the exhaust pipes that run to the rear of the car. I can get photos if you like.

 

[Hib Halverson]

Take the car to an exhaust shop and have them put a sensor bung in the header collector on the same side as the wiring connector is located. Install an O2 sensor in the bung then reconnect the plug. I think Denso oxygen sensors work best.

 

[Antz81]

Thanks, now i can get back to getting everything going properly again.

 

[Peer81]

When your at it, it's some small extra work to make it a heated oxygen sensor. When the oxygen sensor is heated up by the wxhaust gasses the ecm will go into closed loop so putting in a pre heated sensor speeds up this proces

Greetings Peter

 

[Nut]

When your at it, it's some small extra work to make it a heated oxygen sensor. When the oxygen sensor is heated up by the wxhaust gasses the ecm will go into closed loop so putting in a pre heated sensor speeds up this proces

Greetings Peter

Concur.... even when I replaced the stock exhaust manifolds with full length headers I had a heated O2 sensor tapped into the port side header near the collector.

............ nut

 

[Antz81]

Thanks Peter and nut.
I'll get on to that. Previous owners have butchered a few things, so I got lots to do.
Ant

 

[Nut]

Thanks Peter and nut.
I'll get on to that. Previous owners have butchered a few things, so I got lots to do.
Ant

Antz..... did you have to flip the steering wheel or were you grandfathered in? I used to talk to a Corvette friend that lived in Christchurch and I thought she mentioned if the car was old enough you didn't have to convert it.

Don't spoil New Years before the rest of us up here. hahaha :L


............ nut

 

[Antz81]

Antz..... did you have to flip the steering wheel or were you grandfathered in? I used to talk to a Corvette friend that lived in Christchurch and I thought she mentioned if the car was old enough you didn't have to convert it.

Don't spoil New Years before the rest of us up here. hahaha :L


............ nut

No need for it to be converted, once a car is 20 years old it can be imported without any issues. if its newer than 20 years they can still be imported, but there is a few more restrictions. But even a new corvette should be able to come over as is.