Nixon1

Alright..I'll cut to the chase. I get an occasional Check Engine light on a warm engine... So I looked it up...Code 13..Oxygen sensor reports low voltage blah blah blah lean warm engine cruise condition... So I figured, eh what the hell, I'd try a field test. So I start it up and let it idle..completely warm..and plug in the thing. It blinks me out 2 flashes per second..which means either A)No signal is detected from the O2 sensor, or B)I'm running open-loop.
Now keep in mind, the engine was WELL heated and running at about 220, on a hot afternoon..and it said the car was running open loop!? Now, I would figure I would run richer and not leaner that way, but I'm no expert. How easy exactly is the O2 sensor to replace? I hear it's easy, just that you gotta pry the sucker out. And also, is it a clip in sensor or do you have to splice it? Thanks guys...

-My new theme: Why fix it? I'm just going to find a new problem to throw money at then!

MDv6man

Seeing as how the vehicle was warmed up, I would say the faulty o2 sensor is not sending a signal. What happens is the crap going out the exhaust settles on the tip, thus adjusting the signal that gets sent to the computer. That is why many times the car runs rough but there is no code -- the gunked up o2 sensor is still sending a signal and working properly (in theory) but the gunk on the tip is sending the incorrect signal to the computer.

89V6FBIRD

Easy to replace.

Go to your local auto store place, (got a new Bosch sensor from Pep Boys) and make sure it's not the Universal O2 sensor, but the one especially for your car. When you get home, jack up the right front part of the car, and you will see the sensor behind your front passenger tire. Make sure the exhaust is WARM, not HOT, and get a big adjustable wrench to get it off. Unplug the wire, and install the new one. Simple as that.

TomP

That Bosch sensor is #12014, I think it's $20 or $25. Before you go get a new one, check the oxy sensor wire- make sure it hasn't melted on the exhaust pipe. That would cause a short, and the computer would throw a code -and- run lean.

Nixon1

I'll get under there tomorrow and check it out.. I don't usually throw an O2 sensor trouble code, only occasionally when I'm driving.. But it runs rough all the time...although I'd attribute that to need of a tuneup & timing chain as well as the O2 sensor.

90FirebirdV6

i had a hella of a time getting my o2 sensor of all the penetrating oil in the work wouldnt help i ended up warming the car up and i actually did it with the exhaust at normal temp and took a pair of vise grips and finally got it off.

Gumby

get the 3 wire self heating O2 sensor and never deal with it again.

They should never wear out, they just get dirty. self heated ones work faster and stay cleaner.

Gumby

Installing a 3-wire Heated Oxygen Sensor



This is primarily advisable if you have headers. Headers tend to cool the exhast gasses down, which in turn can affect Oxygen Sensor performance. To combat this, a self-heated sensor can be installed, to ensure proper operation regardless of exhaust temp, and also provide shorter times to closed loop operation. I will spare you the details on actually installing the sensor, since it doesn't take a brain surgeon, just a 7/8" wrench, sensor socket, or crowsfoot and some of your time.

The reason for this article is to explain how to properly wire it up. First, you will need the parts. I perfer to use AC Delco parts. The quality is unsurpassed. Also to ensure proper installation, and easy replacement in the future, it is reccomended that you purchase the "pigtail" or connector w/ leads, so that the sensor can easily be plugged and unplugged as needed.

The part numbers for these two items are:

3-wire Heated Oxygen Sensor: 25176708 GM List: $109.00

3-wire Weatherpack Connector: 12126012 GM List: $29.34



You will notice the sensor has two white wires and one black. The white wires can be interchanged, polarity does not matter. Once must go to a good clean ground, either on the body or the engine block, and the other must go to a 12V switched ignition source (Power w/ the key in the "RUN" position). Many people tap into the MAF power wires if you have a MAF sensor, but any "hot" wire in RUN only will work. It can't be HOT all the time, or you will drain your battery.

The black wire goes to the stock PURPLE wire that originally went to your one-wire Oxygen sensor. This is the signal wire to the ECM.




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search ebay for any 3 wire O2 sensor, same thing, might be cheaper.

Nixon1

Thanks for all the tips guys but I went out, bought, and installed a Bosch sensor yesterday...$20. Had to use freakin 3 jacks to get the car up though...first a scissor jack, then I could get the 2- ton floor jack under (didn't have enough clearance to pump it), then I put the 3 ton thingamawhatsit under... The sensor was a b*tch but once I got it loosened up it came out without a lot of effort..didn't even have the car warmed to specs.. Just used a nice little pipe-wrench...fit perfectly. The new one went in easy...didn't go in all the way but I got it in as far as I could. I could barely get both hands in there though to connect the freakin wiring plug! Took me about 10 minutes until I finally managed to get my elbow around the exhaust piping... Car runs a lot smoother now and is more consistent on a cold run..gets smoother engine response now too. Problem is..after I got the sensor in, and took the car around the block, as soon as the engine heated, I threw a code 25. There's always another problem I guess........