[kieran]

Hi Guys, I have had my bike standing for two months in the garage because of bad weather, I went for a ride today and found that my yellow engine warning light stays on all the time, The service manual says to check the DFI diagnosis, but everything seems to be working OK, Does anyone know of a common problem with this warning light, Thanks KIERAN.

 

[Rich T]

You can get the code out following this procedure -- let us know what you find:

 

[kieran]

Hi, Rich, Thanks for your reply, I have done the self-diagnosis and it comes up with the service code 33 OXYGEN SENSOR it says that it sends a message to the ECU, do I really need a new sensor or can I just delete the engine warning light.

 

[kieran]

P.S Would it be a good idea to replace it with ninja 400 02 Eliminator

 

[Rich T]

And I guess my first question would be if you expect that code -- did you remove the sensor, or did it fail, or did a wire break going to it? If the latter, you may need to track that down depending on where the break is, even before you can use the eliminator or a replacement part. I'd do a careful inspection for mice and stuff, and try to follow the wires from your sensor to the main harness.

Also, it is possible this is a "historical" code, not a "current" code, in which case the question would be if you ever started the engine with the sensor disconnected (which would explain it)? A "historical" code will eventually age out of the system and the light will go off by itself, but a "current" code will come back over and over... The way I tell the difference is by clearing the code using an OBD-II reader and harness, but you can also do like 3x 15 minute rides meeting various conditions indicated in the service manual snip below to try and clear it -- the question you are trying to answer is will the code come back, or is it a "one off"?

If you want to try an OBD-II reader and harness, there is info here (the main thing you need to know is there are multiple harnesses -- you have to see if you have a red connector or a white one -- don't use a black connector you find):

(1) DIY Code Reading / Clearing via ODB2 | Page 2 | Ninja 400 Riders Forum
(1) How to clear CEL without driving procedure? | Ninja 400 Riders Forum

 

[Flash Bantam]

P.S Would it be a good idea to replace it with ninja 400 02 Eliminator

I replaced the 02 sensor with a Kawasakibrad.com eliminator plug. It adds 3% more fuel to the Air Fuel Ratio. My Z400 is now an open loop fuel injection. 10,000 miles on the odometer, runs fantastic without a flash tune.

 

[venttiSlim]

I replaced the 02 sensor with a Kawasakibrad.com eliminator plug. It adds 3% more fuel to the Air Fuel Ratio. My Z400 is now an open loop fuel injection. 10,000 miles on the odometer, runs fantastic without a flash tune.

Do you have full exhaust system or with the stock system?

 

[Flash Bantam]

Do you have full exhaust system or with the stock system?

Musarri full exhaust system. Removed PairValve and Evap canister. Free breathing air filter with intake snorkels removed. I always meant to have a full dyno tune but ran out of funds due to life stuff. My Z400 runs very strong as it is and I’m happy as can be.

 

[kieran]

Do you have full exhaust system or with the stock system?

I have stock exhaust

 

[Rich T]

I have stock exhaust

Then you want to check the wiring to the sensor -- make sure everything is plugged in and solid... If it is a historical code, it will eventually age out of the system, or you can try clearing it like above... I'd probably suggest getting an OBD-II reader to clear codes like above if you start replacing parts -- otherwise you're constrained to guessing what codes are actually current every three rides -- which makes for slow diagnosis... There is a procedure in the service manual for testing the oxygen sensor, but it is a bit of a mystery to me.

 

[kieran]

Then you want to check the wiring to the sensor -- make sure everything is plugged in and solid... If it is a historical code, it will eventually age out of the system, or you can try clearing it like above... I'd probably suggest getting an OBD-II reader to clear codes like above if you start replacing parts -- otherwise you're constrained to guessing what codes are actually current every three rides -- which makes for slow diagnosis... There is a procedure in the service manual for testing the oxygen sensor, but it is a bit of a mystery to me.

Thanks for all your help rich, The 3 rides did the trick, and The engine warning light is out, Thanks again.

 

[kieran]

HI all my engine warning light error 33 has come back on after clearing it a few days ago does this mean there is a fault after all. and need to deal with it.

 

[Rich T]

I would think so -- check wires for loose connections first thing -- make sure everything is plugged in and solid...