O2 sensors on turbo Apex not working properly

[Jungers700]

wondering if anybody can give me advice on why my A/F ratio gets screwy, I've got an 06 apex with boondocker turbo, ran it for 2 years never had a problem then one day my A/f ratio started reading in the 13's, stayed there, no matter how much fuel I gave it I couldn't get it to run back in the 12's. So I put a new sensor on and it worked good after that. Got about 4 days of riding with it reading good and now I have the same issue. I know its tuned right because it runs perfect and if I fatten it up it starts running ****ty but it is still showing in the 13's on my gauge. I run a little unleaded race fuel with my 91 octane and sometimes some Lucas fuel treatment for lube. That all just wondering if anybody has any input. Thanks

 

[BigFish BC]

probly lead on sensor some last a few years some a few rides.you need to run decalin run up in your fuel & you wont have issues.
http://www.aircraftspruce.ca/catalog/appages/Decalin.php

 

[Jungers700]

thanks for the link. I may try that either way but all the fuel I run is unleaded

 

[Octanee]

replace your o2 sensor. they get plugged up from lead and stuff over time. Or atleast thats what I've read. But If you got a weird reading first thing I'd do is check connections then if still good... replace the sensor

 

[Jungers700]

I was assuming since all I run is unleaded fuel that my sensor wouldn't plug up with lead in a few days ha. Does it matter where you mount the sensor in the down pipe? could to close to the turbo make a difference?

 

[up-high]

If memory serves(and it usually doesn't!), I put mine 4 to 6 inches from end of exhaust. I think that's right because it was a PITA to get enough distance running a tunnel dump.

 

[Jungers700]

yeaaa and that's probably about what I've got. I guess that shouldn't really make a difference, its probably 5" from the end, but that's also about 5" from the turbo! so say I happen to flip the old apex backwards and it sit upside down for a little while, causing me to get a little oil in my Intake and also out the exhaust, would motor oil on the sensor screw it up permanently you think?

 

[up-high]

Yes it will. Did you maybe happen to do that?

 

[Jungers700]

yep I know I did this last time with the new sensor in, dont recall that the first time the sensor went bad, but chances are I did ill go with that and try another another sensor again