I’ve been off here for years cuz I sold my 250s but now I miss it and bought 2023 300ds. I just purchased the barker exhaust and dyno jet fuel controller for the lid less set up from barker it has there tune. I was wondering if I should delete the o2? They said no but when I bought the same set up for my 2018 250s it came with o2 delete.

 

The computer fuel injection depends upon various sensors to map the correct fuel sent to the combustion chamber to obtain the stoichiometric air:fuel ratio (~14.7:1) in the combustion chamber; one of those crucial sensors is the O2 sensor, which detects exhaust oxygen content ... and sends that reading to the computer ... which uses the exhaust oxygen content to adjust fuel going to the combustion chamber. Remove the O2 sensor and the computer has no way to adjust the fuel correctly.

 

Dig around here a bit, there has been some discussion. It might be in the KLX250 forum, but does have some new 300 riders too.

 

I believe the O2 sensor will try to compensate for the manual settings on the dynojet.
I run a custom exhaust with the stock 02 sensor and no controller because I ride for transportation, so the engine is always operating in closed loop mode where the sensor controls the a/f mixture. I get excellent gas mileage with 75mpg average in Winter and 85mpg in Summer.

 

I installed the dyno jet fuel controller and removed the O2 sensor. Had it dyno tuned and the fuel controller takes care of all the fuel needs. So O2 sensor isn’t needed.
Also did the same on my R3

 

I sold my 22 but now have a 23. I did the barker full exhaust with the EHS tuner , removed the secondary throttle plates, took off all emissions and air injection. With this set up they said to leave the O2 sensor in. I do have a delete plug but I just left it in.

 

I also installed a tuner but no dyno. It positively slaughtered my gas mileage. I was getting 80 mpg, and now am barely getting 60. So I'm going to lean it out a little and see if it improves.

 

That’s a huge hit on MPGs wow