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MPI turbo 850 400 miles report

snow4shover

Well-known member
Premium Member
Dec 13, 2007
270
226
43
Belgrade, Mt
Chris, (Shover)
What do you think about the long term accuracy of the typical Bosch Lambda sensor left in the oily exhaust stream of this eTec ?

A few years back, in a conversation with Bosch, I was told that the sensors will function and then degrade without the ability to know when they will start to provide inaccurate information.... and noted oil blow-by as the #1 killer of accurate readings.

Kind of the basic concern on monitoring 2 stroke exhaust. I've always been dubious of people saying "I've been running a AF-gauge on my 2-S for for years without issue" when they've never done a comparison to a fresh sensor. For me, I feel that on a 2 cycle engine, the commonly avail AFR gauges are great tuning tools, but not to leave the sensor in the exhaust stream.

I know you are in the business, and much more experienced with the "hands on" control and monitoring systems than me... so I would defer to you, sincerely, with a thoughtful explanation of this if you can take a few minutes to help me understand better...

.

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.
 

BIG JOHN

Well-known member
Premium Member
Nov 26, 2007
1,953
1,146
113
Minnesoooota
SHR has plenty of clutch parts for the MPI turbo...

INC custom adj ramps and helix recomendations...call to chat-BJ
 
F
Nov 27, 2007
2,495
712
113
medicine hat
Biggest problem with Bosch we found is rolling sled and having snow cool the tip rapidly, take a new sensor out in less than a day..

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.
 

snow4shover

Well-known member
Premium Member
Dec 13, 2007
270
226
43
Belgrade, Mt
400 Miles O2 sensor

Here is the picture of the oxygen sensor that I promised. Sorry it took so long. This is running 11.6 to 12.0 : 1.
 

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madmax

Well-known member
Lifetime Membership
Nov 26, 2007
4,485
3,137
113
Salt lake city
Not Mac and don't work there. MPI is close to my house and I've known Mac for a few years. When this doo turbo showed up last summer I got really interested and got the first one. Got over 600 miles on it now.
 

christopher

Well-known member
Staff member
Lifetime Membership
Nov 1, 2008
81,399
27,151
113
Rigby, Idaho
Kind of confused here

MadMax.... are you "Mac" at MPI or do you work for/with MPI?
I had assumed that you were the owner of MPI.


Thank you for your input on this kit for our members!



.



As I told you in private when you asked, MAC the owner of MPI does not participate in social media and hasn't used his Snowest account in years. Mad max is an MPI enthusiast
 
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