Uhmm.. broken o2 sensor

[Blakthorn]

crawled under the car to check things out and noticed my passenger side o2 sensor is plugged into my upr x pipe....but guess what...the other end is cut and not plugged into the car..i always skimmed over this because i just checked the x pipe to see if they are there

so for about 4 months i have been running the car with only 1 o2 sensor, i have an 87 so no check engine light and i was clueless

What happens when only 1 sensor is working, any negative affects to the car?

 

[DeVus1]

Probably not. The older engines are more forgiving with things like that.

 

[Daggar]

you may be stuck in open loop and not even have realized. What's your gas mileage been like?

 

[Blakthorn]

Daggar, whats open loop? My gas mileage is average, leaning towards above average slightly..

 

[Daggar]

Open loop is the mode the EEC goes into during startup and when cold. The car runs on preset fuel tables and takes input from a very few number of sensors. A lot of things have to be "right" in order for the EEc to go into closed loop and vary spark and fuel tables to run as effiently as it can. Something as small as a bad ECT sensor or coolant temp sensor can cause the EEc to remain in open loop. What I don't know, is if having only one of two 02 sensors operating correctly will cuase that condition. If the motor is running strong and not killing you in gas then leave it. If you ever go to hook that sensor back up, it will likely need replacing. running that long wihtout a preheater in teh exhaust stream has surely ruined it by now.

 

[Blakthorn]

i plan to replace them both, what should i expect, if anything?

 

[Daggar]

If anything (assuming the EEC isn't able to do it's best with just one 02), you may see in increase in mileage.