84project

I have a stock 1984 12a base model with a 4BB carb. I knocked the 02 sensor off the exhaust system when re-installing the heat shield. Does anyone know exactly what running without an O2 sensor does to the fuel mixture? The car seams to run fine without it but I am conerned it may lean out the fuel too much and my manual does not provide that level of insight. Any thoughts?

gsl-se addict

iTrader: (3)

It's not really an O2 sensor (looks like one, though). It really is a thermocouple used to measure exhaust temperature for the emissions control unit. I'm not exactly sure of its function (I imagine it is to detect lean running conditions), but the only thing it will impact is emissions (and probably won't even impact that under most conditions).

spankle my wankle

i dont even have one and it runs fine

djessence

same here, i no longer have it. That being said my emissions is removed.

Pretty sure as addict said, its an exhaust temp sensor. Even newer cars can run without them, itll just throw an engine code.

gsl-se addict

iTrader: (3)

I looked into it more:

The thermo sensor is a temperature switch. It is open (i.e. not connected) when:

- exhaust temp above 770 C (1418 F) for manual transmission
- exhaust temp above 740 C (1364 F) for auto transmission

It looks as if it only impacts the relief solenoid (blue). When open (or disconnected), air from the air pump will not be injected into the engine ports/cats (bypassed back to air cleaner). As far as it shows for testing in the FSM, it looks like this function is only at WOT (I would need to verify the direction of the 12A throttle sensor to be sure).

So basically it cuts air to the cats when they get too hot. The heat hazzard sensor under the passenger floor serves a similar funciton. I guess that you may be okay without it. The cats may not operate correctly (starved for air) under certain conditions, though. If the cats have been hollowed or an aftermarket exhaust has been added that has no cats, then the sensor is not needed.

'84-12A-GSL

Only fuel injected cars need O2 sensors, and they're generally located on or close to the exhaust manifold or header.

I believe you can use them on carb cars for tuning purposes.

Our exhaust temperature sensors are located on the mid pipe. I removed mine, cause my after market exhaust didn't have a bung for it,

84project

Thanks for the input... makes me feel better. I had the caytalic converter gutted once the car was classified as antique and did not need emission testing. It looks like I will leave things alone.

mikewoodkozar

You will be okay, unless it is driving you nuts, then replace it.

djessence

replacing it will be very expensive. those sensors are not cheap in any way shape or form.