On all my previous turbo 2 strokes the oxygen sensor was post turbo. I ran everything from 91 with octane boost to 100ll to race gas and when i removed my sensor it was dry / cardboard brown in color. The MPI kit does have the oxygen sensor pre turbo. I will remove the sensor tonight and take a picture of the sensor. In my experience there shouldn't be that much oil in the exhaust. If there was then stock sleds would have oil dipping out of the pipe all the time. I know when you are first breaking sleds in they run a ton of oil and you will typically see a few drips to a puddle under the Y-Pipe. The kit was installed on my sled since day 1 and I now have over 400 miles on the sled so it will be very interesting to see what the sensor looks like.
<b>Here are the typical sensor failures I've seen before: </b>
<ul style="list-style-type:square">
<li>1. Coolant hitting the sensor</li>
<li>2. Damage sensors due to rolling the sled/utv/atv or dropping sensor when installing. They do not like vibration or sudden hits.</li>
<li>3. People thinking they need to clean the sensor so they spray it with brake clean.</li>
<li>4. Improper controller over the heater circuit. This is the only main difference from 4.2 to 4.9. The 4.2 had a poor algorithm that controlled the heater which would degrade your sensor life. The 4.9 has a revised heater control algorithm to help with sensor life. Everyone will agree with me that there are other differences but for what we are using it for there is not. 4.9 does have more data points but only in the extremely lean side of the sensor from 20:1 to 42:1 which is made for Diesel Applications.</li>
</ul>
In my mind if people are that worried then you should have a spare oxygen sensor. You should be able to buy them for $60.00 to $80.00 for a replacement. If people can not get this price please let me know. I will find it for them at that price.
