Ok I changed my O2 sensor about a year ago when I got a code 13 and it fixed it. Now I the code again and I am about to change the O2 sensor again. The car is an 89 firebird with a v-6 and auto tranny. My parents owned the car since it was brand new. Since 89 it has had several o2 sensors a few under warrenty (one when it was very new) and a few they had to change and pay for themselfves. It seems like every other year it needs a new O2 sensor and more recently every year now. I think the car has had over 5 or 6 sensors and I am about to put another one in. What is causeing this car to go through so many. Is it a flaw in the system or design (causing a voltage spike or something) The SES light comes on and goes off but it hasnt gone away it will come on every now and again. My 85 firebird v-6 manual tranny had the orginal o2 sensor right up to the time I pulled the motor for a v-8. So why does this 89 firebird go through so many so often... and is there some parts store that sells a lifetime warrenty O2 sensor or even a couple year warrenty? They one I got has no warrenty. Which is the best made sensor to put in that will last the longest? I beleave it has had several OEM sensors and a few aftermarklet and they seem to last the same. Anyone who has a theory on why this car is going through so many and how to fix it is welcome to give me ideas... thanks very much!!!

 

An O2 sensor is a tool the ECM uses to moniter the exhaust gas. It sends signals to the ECM to adjust the fuel mixture to a set point. If it sees and increase in unburnt fuel and the ecm cannot adjust the mixture it will send a trouble code in the form of a check engine light. The same will happen if a lean condition appears. It along with the code will tell the tech there is a problem usually it is not the sensor the sensor just finds the problem and sounds the alarm especially if there has been soo many replaced in the past. Right off hand I'm drawing a blank for 13, (10 beers will do that) I beleive its a rich condition. Leaky injectors partialy plugged exhuast can all atribute to your many O2 sensor codes. IF you do decide the just replace the sensor as many people do make sure to use a quality part, Neihoff and Beck Arney are the closet to a factory replacment and usually are in stock at Checker (CSK).

 

Oh ok, I thought the o2 sensor code just ment the 02 sensor was not working correctly. So why would replacing it work to stop the code for a year if an underlying problem exsits. Shouldnt the code set off if you change the sensor and you still have the other problem. Well this wasnt the case in all the other changed out sensors but my cat has pieces rattling around inside and I am going to change it as soo as the part from summit is delivered. I probably will change the O2 sensor anyways just to make sure. I will follow your advise and see if I can find some of the brands you recommend. The most common one I see is Bosch though. Are they any good?

 

I've used Bosch #12014 for about 10 years, never a problem.

Code 13 is for an open oxy sensor circuit- meaning, the engine isn't getting feedback from the oxy sensor. This is "normal" when the engine's cold. The engine has to be warmed up for the oxy sensor to work.

Since I'm home, I can grab my http://www.helminc.com manual, and give the exact specs:

Code 13 sets when all of the following are true: (a) engine is at normal operating temp, (b) at least 2 minutes engine run time after it was started, (c) Oxy sensor voltage at ECM terminal is between .35 and .55 volts, (d) TPS (Throttle Position Sensor) signal is above 6% (about .3 volts, meaning, you're pushing on the gas), and (e) all of these must be met for at least 60 seconds. So basically, that means you've been driving the car for at least two minutes, and you're on the highway with your foot on the gas (not just stopped at a stop sign) for at least a minute.

So; here's what I'd suspect. You've changed that oxy sensor out a ton of times. I'd get a digital volt meter, and check the wire between the ECM (computer) connector and the oxy sensor connector. I bet the wire's bad.

In fact, you might not even want to test the wire! It's buried in the engine harness. Here's what a GM tech would do- they'd put a brand new wire in, and just cut the ends of the old one. It's faster for them to add a wire then it is for them to try and pull the old wire out of the engine harness. I'd give you the ECM connector/pin to test (with a DIGITAL meter, Radio Shack has a cheap one for $10), but your '89 computer is different than my '86, I wouldn't want to give you the wrong pin. (Your computer has a speed density PROM, -and- it's got a higher data transfer rate than mine.)

You should (and EVERYONE SHOULD!!! HOW MANY TIMES DO I HAVE TO MENTION IT???) pick up the GM Service Manual from http://www.helminc.com for more info, BUT: Basically, from the diagnostic chart, they have you check the voltage from the ECM. If the ECM checks okay, they say "bad oxy sensor or oxy sensor connector." You've replaced that a few times already... so I don't think it's that at all. I bet it's that wire between the ECM and the oxy sensor; should be a purple wire. Buy a roll of wire from Pep Boys or Autozone that's the same thickness as the current purple wire, and use it to "replace" the factory wire.

You'd probably want to cut that purple wire at the ECM and leave about 6 inches on it, which will allow you to solder (or butt-crimp, don't just twist the wires together and use electrical tape!!!) your new wire on. At the oxy sensor end, see if Pep Boys/Autozone carries the single-terminal female weatherpack connector case and pin- and crimp that new connector onto the new wire.

Hope that helps!

 

Oh SSC, you're thinking of codes 44 (lean) and 45 (rich). Fun fact- if the oxy sensor wire or connector melts on the exhaust, that grounds out the oxy sensor signal wire, and can throw code 44. Guess how I know!

 

The 1st accell ignition module I installed went out and got a code 45 within 30 days of installing it and I got another one (underwarrenty) and all is fine. So could that be a possible cause of the wire? I will test the wire though. Sounds like it could be a problem. Also could a bad ECM sendinding out too much voltage be a possible cause?

 

Yeah a bad ECM could definately be the culprit... hopefully it's not, though. My dad's old '87 Oldsmobile 2.8 MPFI would occasionally throw a knock sensor code; I replaced the sensor, connector, AND the wire to the ECM- and still got the code. Everything in the GM book's diag chart checked out fine- except "check/replace ECM".

You sure you got code 45 with the ignition module, and not code 42?

 

yo know I think your right it was a code 42

 

Does anyone know off hand what gauge wire the O2 sensor is?

 

Yep, I'm in OBDII land these days, dont see many pre 96's come through the shop anymore at least ones that havent been old school'd.

So you havent had any problems with the BOSH sensors at all? Those and a few other autozone brands going bad days after install ended all relations with those stores and thier "discount parts". I'd rather walk then install another Wells coil.

 

LOL... yeah, all those Bosch's worked fine. Supposedly Bosch makes the GM one; don't know how true that is tho (I never looked into it).

The first oxy sensor I got in 1994 (car blowing black smoke out of exhaust, it fixed it) was one of those universal replacement ones, it didn't come with a connector, I had to re-use the factory pigtail. What a pain that was! At least the Bosch 12014's plug right into the harness.

 

Tom when I went to the parts store and picked up a bosch one they listed 2 different numbers for the same car. The 12014 one which the parts counter guy said was an OEM and a second cheaper one that wasnt OEM. the cheap one was 17.99 and the OEM one was 19.99 so for 2 bucks I went with the better one. So I think your right bosch makes the GM one

 

Many people screw this up...the O2 DOES NOT detect fuel in the exhaust. It only detects the concentration of Oxygen...hence the name Oxygen Sensor. if there is a high amount of Oxygen, the O2 thinks that there is not enough fuel to mix with the air and asks the ECM to make the mixture a little fatter. If there is little or no O2 in the exhaust, it thinks that there is too much fuel for the amount of air, and asks for it to be leaner.

That means that if you have a misfire, then all the air that is entering the cylinder is just pumped right out in to the exhaust, the O2 sees that there is a lot of Oxygen, and asked for a righer setup, but since you aren't buring the air that is going in, it's an endless loop...that is until the ECM reaches it's maximum ability to compensate for the air, and gives you a lean code. Same thing goes for a malfunctioning diverter valve for the air injection system.

 

Another thought...does the car smoke on start-up...even a little?

Anything that might possibly cantaminate the O2 will make it wear out sooner.

Here is a test that you can do at home..but be careful because you can get burned being near the exhaust.

Connect a digital volt meter with the red lead stuck into the connecter for the O2, just shove it in the back and becarful not to rip the wire apart. put the black lead on the exhaust pipe/O2 nut area. the red lead is now connected to the component signal wire and the ground connected to the component ground...in parallel with the sensor circuit. Start the car and watch the meter, as the car warms up, you should see the voltage alternating between ~0.15 volts and ~0.85 volts.

If you don't see it swinging, ground A & B on the ALDL while the engine is RUNNING. You will see the check engine light flashing. If it is flashing very fast, then you are still in Open Loop. If it starts blinking about once a second, then you are closed loop and the O2 is controlling the mixture. If the light is on longer than off, then the ECM thinks you are running rich and if it's off longer than on, then the ECM is "running lean." Remember, this is all based on O2 input (that voltage that we are reading)

If the O2 is not varying between those voltages by the time you should be closed loop, it's toast.

Just remember, anything that would contaminate the O2 WILL shorten it's life, so even if you burn a little oil, it's gonna kill that O2 quick. They are more fickle than most women.

 

Well I dont see even a little smoke being burnt... Its too late to do that test since I am in the middle of taking it out... the thing is very stuck and I beat off the end and using an impact wrent to get it out. Not working very well yet so I am soaking it in penatrating oil to try to get it out. Well anyways I did test the OHMS on the wire and got 8500 OHMS is that right... seems alfully high?? Can someone tell me if thats correct... or is that causing my sensor to go out? If no one know could someone check their ohms on a known good one. I did it by diconnecting the O2 sensor putting one lead on the wire going to the computer and the other grounded to the body... simple test takes only a few mins. Just dont know if 8500 OHMS is correct or in range

 

Does any know???? 8500 OHMs on the O2 sensor wire to the computer, is that correct? Could some one do that test for me to see what they got on thier car, if you are already doing soming underneath anyways. Just gotta disconnect the connector and put on lead on the wire and one on the fram.... make sure you get a good connection. I would really appreciate this!!