Does 85 GMC 305 have O2 sensor ?

[Slonaker]

Originally Posted by irishman999

Thats what my truck has also, I keep seeing post on here mentioning computer controlled quadrajets. The o2 sensor is going to detect the right mixture of fuel and air and send a signal to whatever it is metering the fuel. So the electronic pulse goes from the o2 sensor to the vacuum operated mechanical carburator and then what happens?

Could someone explain what the unit poking out of the top of the carb is? Its got a plug for a couple wires, it looks like a cylinoid.

I can't say what the plug on yours is because you are so close to CA that you might have a CA emissions truck. On mine the plug is (well. was...) not a computer control. I think it was related to the accelerator pump.

People often assume it is a computer controlled quadrajet because it has a plug, but it is not. Apparently on CA emissions trucks, they are computer controlled and have a check engine light, computer controlled carb, and an O2 sensor. Mine has none of those, and never did.

Slonaker