EVO8_PR

iTrader: (5)

How long has your wideband o2 sensor lasted? I bought one about a month ago (first one lasted about 4 months) and yesterday it too said farewell. This new sensor saw about 200 miles and 4 gallons of VP C16. Did a run across a faulty sensor or has anybody else had the same experience?

I have my sensor installed at approximately between the 2 and 3 o'clock position looking from the rear, about 3 inches after the hangers of my DC Sports DP.

kjewer1

iTrader: (4)

The general rule of thumb is to get 1000 miles of pump gas on a sensor before running any leaded fuel. This has ALWAYS worked for me on stock type sensors, and until recently also worked on the Bosch sensors. Starting at the beginning of last season though, the heaters in the bosch sensors have been constantly going out on me. I get about 3 months each. Couple that with the fact that the sensors have doubled in price in the same one year period... This is getting old. I though about upgrading to a newer version of my Techedge WBO2 hoping to maybe get a better heater control cicruit or something. I have also considered moving the sensor up to the O2 housing, thinking that the heater is running full tilt to keep it hot in the rear location (the heater output LEDs seem to support this theory). Who knows.

Sensor number ~5 went in yesterday.


Edit> The local VW dealer's parts guy did mention a Bosch recall on these sensors about 3 months ago. Perhaps they all went to ****. I use VW part number 021-906-262b, for reference.

Nez136

iTrader: (10)

25k on my sensor and im still good. I've ran about 15 tanks of leaded fuel.

kjewer1

iTrader: (4)

That reminds me. On the sensor I originally put in the EVO I had run several years and probably 50-70k miles in the 2g, running leaded fuel once or twice a week. The sensors have definitely gone to **** in comparison, or something is different about this car than the 2g.

.50 Cal Cow

iTrader: (2)

Sorry to hijack but how do you know when an wideband sensor has sh*t the bed? Just really off the wall readings?

kjewer1

iTrader: (4)

Biggest tip for me is the sensor will work while cruising, then go full lean at WOT. Looking at the controller, I have an error light for the heater control circuit. The last failure was even more obvious, I had a Heater Circuit Open error right on my display...

EVO8_PR

iTrader: (5)

Both of mine just stopped fluctuating readings stayed static @ a reading.

EVO8_PR

iTrader: (5)

kjewer1, what o2 controller do you have?

kjewer1

iTrader: (4)

I've had that failure mode as well. I think it stuck at 13.4 leaving NOPI... I had a heater error then as well.


Edit> I'm on a very old Techedge 2A0, probably got it 5 years ago. I have considered moving up to one of thier newer units.

silverofs

iTrader: (3)

i have been using the vw sensor also & mine goes out all the time too just like you stated^^^^^ maybe i will try my next one closer to the motor & see what happens

jfitzpat

The Bosch LSU sensor is rated for about 200 hours in 100LL (AvGas). However, in practice I get just over 100 hours. This is presumably because air cooled aircraft engines run pig rich. I use our wideband, so I know when my sensors are giving bogus values or have failed. If your wideband does not report sensor errors, you could hit a smog check station (at least here in CA) and try 1% calibrated gas periodically.

The problem with lead is that the O2 pump creats a coating on the Nernst cell, stopping catalytic activity (required for measurements). Bosch sensors use a patented planar construction. This makes the sensor very fast (small chamber delay) and very resistant to gas pressure errors (about 1/5 that of NTK UEGO sensors), but it also makes for great sensitivity to contamination (lead, silcone (which tears down to SO, then becomes silicon dioxide), etc.).

NTK sensors use a thimble type construction. This makes for much slower sensor speed, and a lot more sensitivity to gas pressure errors, but it takes quite a bit longer to ruin the sensor by contamination.

Closer to the engine is probably a bad thing. An often overlooked spec is Bosch LSU max bung temp. The max gas temp is 800-900 degC, but the max rated bung temp is about 300 degC cooler. Exceeding this temp (far more common than exceeding actual gas temp) shifts readings and creates cracks in the ceramic body of the sensor. Again, our wideband measures this, but even if yours does not, it is worth keeping track of and avoiding. Also, there is quite a bit of evidence to suggest that lead build up more slowly with cooler gas temps.

As far as good/bad, it is really hard to say for sure, unless your wideband reports errors or you periodically check with calibrated gas. Checking proximity to stoich (14.7) is pretty much meaningless for closed loop operation, because this is the one place that the sensor will tend to stay pretty accurate, even with the rest of the curve is shifted 1.0 AFR or more.

-jjf

spoolint78

iTrader: (37)

ya the bosch sensor's don't last long with race gas for too long.
But they are fairly cheap to buy.

The ntk sensors last long,but they are in the 200usd price range.

Sharif@Forged

iTrader: (1)

From our experience, NTK sensors last far longer than Bosch, particularly if the sensor is exposed to too much heat >900F, or you run even small amounts of leaded fuel. NTK's are pricey, but a super nice sensor. Longer lasting, much faster warmup, faster response time, and very consistent over time. The draw back, is that the sensors, and the controllers are much more expensive.