Contour Enthusiasts Group Archives Forums General Troubleshooting Symtoms of failing O2 Sensors???

Anyone know the final stage of O2 sensor falure before vechicle is rendered complete usless untill repaired? I apparently need mine replaced and they supposedly have little heaters in them which makes oem 02's a whopping $250 a peice (in canada). I have no idea how to diagnose this and I don't want to pay someone to fix it. I did get a code that suggests near total failure on 1. They need to be replaced in pairs and aftermarket O2's don't have the heater nor a decent wire harness. Want oem but want to eat too!

First, if you posted the code(s) that were read it would help answer your questions.
Second, I don't know where you got your price, which I assume included installation, but the sensors can be purchased for considerably less. Try Canadian Tire or a NAPA store.
Third, they do not have to be replaced in pairs.

In regards your general query, faulty O2 sensors will reduce power and fuel economy and may have a detrimental effect on cayalytic.

I don't know the codes off the top of my head but the reader said they should be replaced in pairs. Any o2's you get from canadian tire will not be oem there for not have built in heaters which I understand is almost a MUST for contours to function properly. I am not trying to act like I know all about this car but I did get this info right from a good mechanic who I have been frineds with for 9 years.

Try this:
http://www.boschusa.com/AutoParts/PartFinder/PartFinder.asp

and see if Canadian Tire (or any auto supply store) can get the one for your car.

Replacing both might be a good practice on a car with only two O2 sensors, but I haven't heard of anyone replacing the four that are on my cars and later models, when only one is acting up.

This from the home page FAQ gives a link to the 3 digit codes your car gives.

http://www.contour.org/FAQ/FAQ.php?s=probs&display=checkengine

Thank you very much. I'll check that out. I really apreciate your response. If I can get them at a reasonable price and done, I'll let you know. Do you know if the scan should pin point which sensor it is? Seems my mechanic friend has been proven wrong!!!!

Yes, also re-read I was editing as you were reading.

You're the best! Screen shot/book mark!

Mine's a 95 se though...you think they still apply?

Click on the link to get 3 digit codes for '95, the 4 digit are for '96+.

on that same note fellas - i dyno'd last week, and this weekend my car started hunting for idle
today...the dreaded CEL. i'm thinkin' it's the O2 and I'll go to autozone (they check CELs for free) soon. What are your thoughts? O2?