Reduce the ignition advance at idle as much as possible in-order to reduce the vacuum in the intake plenum. By doing this the exhaust pulse back during overlap will be reduced. After doing this my sensor have not failed.

This is where I am at on this experiment. Sensors are living just fine. But I believe I am getting a false lean reading for some reason.

So lean that it does not even register at idle. Readings at part throttle and full throttle jump wildly between 14.5 and 15.7. I wonder if the reading fluctuating up and down 1 full number every half second is normal.

Still reading my plugs and think I am safe. Just not sure what to think of the O2 readings I am getting or why they are off so far. Maybe the sensor is not getting a big enough sniff of air.

Anyone?

Going to have my buddy weld the sensor in my headers now. Whats the worse that could happen? The mild steel outer pipe rusts around the weld. Its on the very top of the header anyways.

Once you get the bungs welded in, maybe you could try the sensor in the bung on one side, and the tube on the other, and compare readings to see if it is throwing you off. Or you could do both on the same side to eliminate the possibility of one side running leaner than the other.

Any chance you could install one in the bung on the header and let it idle for 30 seconds or so with no water to the header, just to take a good reading at idle?

I was getting about ten hours of running before the o2 would die while in closed loop I tried the extension with a 90 degree, engine would run like crap. I finally talked to Alex Haxby, and he suggested backing the timing way off at idle speeds, both in and out of gear.
Now the EGT @ idle is 650. In other words I am burning the water out of the stainless marine manifolds allowing the sensor to live.
I don't know if retarding the idle timing would work in your application, but it worked for me so far.

(Fingers crossed)


Steve

My sensor is too close too the open end of the pipe causing the lean readings. (fresh air reverts back into the pipe)

Yep, that's the reason that so many of the tuners use the probe to get it up further into the exhaust.

I have made some revisions to my sniffer and things are starting to progress. A little bit of trial and error

Didn't know if you saw my thread on Lightnings and reversion, but if the amount of moisture that I am seeing in my primaries is fairly normal, then I don't see any way an O2 sensor could live very long anywhere in that exhaust stream. Still trying to find the root of my problem, so yours may be dry, but that is a fairly mild cam that I am running that shouldn't have that much exhaust overlap. Perhaps it is the 4.25 stroke that is the tipping point.

I did see your thread. Actually my sensor has withstood more moisture than I originally thought it would.

I found when I stuck the tip of the sniffer 3" into one of my header pipes. Which would put it 3" before the collector i was still getting some moisture. It sounds like most guys are not able to keep a sensor in their exhaust long term.

My motor is all stock with the exception of the Procharger.

In my experience water only kills them when they are powered up. One of mine took a dunk under water while I was removing it on the lake. Was not powered up at the time! It still works fine.