keep eating o2 sensors?

[Raginstang]

hey, for some reason, my car goes through oxygen sensors like kids and candy. I just replaced them like 6 months ago and they are bad again, and before that they went bad sooner. I have no cats and quite a few mods, do you think all the raw fuel is killing them? any suggestions to help? at like 40 bucks a pop, evey few months, it gets expensive help!!

 

[89MustangGX]

What makes you think they are bad?

 

[rowdie- stang]

My car was doing the same thing a few years back and it turned out to be the harness going back to them was to close to the headers and it was burned bad enough to make them short out

 

[jrichker]

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $33.

Code 41 or 91 - O2 indicates system lean. Look for a vacuum leak or failing O2 sensor.
The computer sees a lean mixture signal coming from the O2 sensors and tries to compensate by adding more fuel.

The following is a Quote from Charles O. Probst, Ford fuel Injection & Electronic Engine control:
"When the mixture is lean, the exhaust gas has oxygen, about the same amount as the ambient air. So the sensor will generate less than 400 Millivolts. Remember lean = less voltage.

When the mixture is rich, there's less oxygen in the exhaust than in the ambient air , so voltage is generated between the two sides of the tip. The voltage is greater than 600 millivolts. Remember rich = more voltage.

Here's a tip: the newer the sensor, the more the voltage changes, swinging from as low as 0.1 volt to as much as 0.9 volt. As an oxygen sensor ages, the voltage changes get smaller and slower - the voltage change lags behind the change in exhaust gas oxygen.

Because the oxygen sensor generates its own voltage, never apply voltage and never measure resistance of the sensor circuit. To measure voltage signals, use an analog voltmeter with a high input impedance, at least 10 megohms. Remember, a digital voltmeter will average a changing voltage." End Quote

Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. You'll have to pull the passenger side kick panel off to gain access to the computer connector. Remove the plastic wiring cover to get to the back side of the wiring. Use a safety pin or paper clip to probe the connections from the rear. The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter.

The O2 sensor ground (orange wire with a ring terminal on it) is in the wiring harness for the fuel injection wiring. I grounded mine to one of the intake manifold bolts

 

[Raginstang]

I used a scanner and got a code for oxygen sensors always indicating rich, not switching, don't remember the code number though, and my right bank air/fuel monitor is not switching like it should

 

[Daggar]

If you're truly eating 02 sensors that quickly, my guess would be that they are not getting power to the heating wires. My 02 sensors are 19 years old and yes... I'm sure they're functioning because the WB02 tells me that AFR is right where it should be.

 

[TrophyHead]

What brand did you buy?

I would stick with Motorcrafts....there a little more pricey but IMO worth it.

 

[ninety15.0]

my car was sort of doing the same thing but it was only burning one the right one. The code i kept getting was lean condition on the right bank. I tried a bunch of stuff to fix it but i ripped the motor out and im building a new one...so i never figured it out...but i feel for you it does get expensive especially when u are replacing both at the same time every couple months.