last night i noticed that there was a sensor of some sort coming out of my headers on the drivers side (was underneath car when i noticed it). is this the O2 sensor? i also noticed that the wire for the sensor was broken and not connected to anything else. Where is this wire suppose to connect to. if the 02 sensor isn't connected shouldn't the choke light be coming on?

 

That should be the O2 sensor. Look for another piece of wire that looks similar. It should come over the engine from the passenger side to the driver's side in front of the carb.

If not working, your check engine or service engine soon light should come on. If the bulb is burnt out, well, it won't be coming on. When your turn the ignition to the "on" position before starting the engine, the light should be on.

 

does the wire for the O2 sensor run up to the top of the engine? if is does where abouts does it run up to, we couldn't see the wire hanging down but maybe i can trace the wire from the top of the engine down.

 

I did the choke light check and it did come on when the key was in the On position so i know the bulb isn't burnt out. I though for sure that if the O2 sensore wasn't hooked up it would throw an error. I also had the car de-emmissioned a while back, a high performance shot removed a bunch of the equipment that was recycling the exhaust gases since the belt wasn't even hooked up. Is it possible that they removed something the O2 sensor connects to which is why there is not reading coming from it?

 

The only way anyone can get away without an 02 is if they burn a chip to keep their car in open loop the entire time.

 

hmmmmm interesting...The O2 sensor is a sort of plug in the exhaust pipe leading down from the driver side header correct? Could this be something else that i am seeing? What is the O2 sensor suppose to do, if it not working properly what sort of symptoms should i be experiencing?

 

There is both a choke light, and either a check engine (CE) or service engine soon (SES) light. Both lights should come on when the ignition is on w/o the engine running.

The "plug" in the driver's side exhaust should be the O2 sensor. Look for another piece of wire that looks similar to the one coming off that "plug". The wire comes over the engine from the passenger side to the driver's side in a harness bundle in front of the carb. (Why do I feel like I'm repeating myself here?)

The O2 sensor provides information to the computer about the combustion mixture ratio. If the O2 is not connected, the SES or CE light will come on, and the car will run rich.

 

thanks for the reply, i'll double check to see if i can find the wire coming from the carb area. If that check engine light is burned out, is it a matter of taking off the gauges and the bulb sits right behind the check engine display...i can see this being time consuming taking on the dashboard etc...

 

Someone may have to help me here.

You're in Canada, right? Was the car originally delivered in Canada? Is it really "HO", as in L69, VIN code G?

What I'm getting at here is, many Canadian delivered cars did not have a computer. However, the HO may have - I'm just not sure. If you really have a VIN code H LG4, and the car was delivered in Canada, it most likely does not have computer controls. And, the "headers" (if it really does have aftermarket headers, instead of what you referred to as headers actually being the factory exhaust manifolds) that were put on it had the port for the O2 sensor, but since the car didn't have a computer, an old sensor was just screwed into the hole to plug it. Therefore, you don't really have any problem at all.

Help me out here, eh?

 

Well the car has an HO body and decals on it when i got it. I'm not sure if the motor is original since there is a GM GoodWrench tag on the motot (someone mentioned that the tag indicates it could have been rebuilt, whether they rebuilt the HO or just a normal 305 i have not idea). The speedo is in MPH so i'm assuming the car was originally from the US. I remember while back that the O2 sensor was causing me problems an had it replaced i think. The headers that are on the car now are aftermarket. I also had the car de-emissioned so much of the equipment for recycling the exhaust gases is not in the car anymore, when i got the car the belt for the emmissions wasn't even on.

Lemme know if this info helps. I also checked the lights that were on then i turned the key to On and noticed that only the Choke light came on.