Galaxy 2.3 Correct Octane Rating

[billyboyroy]

I took my galaxy into the garage today because it is running poorly (hesitant). They read the codes - the heated oxygen sensor appears faulty (both too rich and too lean) and the computer also read "This vehicle has been adjusted to run on 91 octane fuel". Can anyone tell me if this is normal? Could this be the source of my problems?

[Saif Rehman]

IIRC, it should be 95 octane.

[Willie Krashitt]

If you are talking 2.3, the standard set up is indeed 95 octane. The PCM is recalibratable for 91RON, as some markets where the Galaxy was sold (eg. Germany) still sell the stuff. If yours has been reconfigured for 91RON, it does beg the question why, as it isn't sold in the UK. Was the car previously used in Germany?

 

It certainly won't be the cause of your poor running - the codes tell you that the lambda sensor is faulty, or at least the wiring to it is - so is 99% sure to be the cause of that, but the retarded ignition timing for 91 RON will make the car less responsive at lower engine speeds and not help the fuel economy either.

 

As far as I know though, getting the PCM reset to 95RON requires WDS or IDS at a main dealer.

 

George.

[billyboyroy]

Thanks George, To my knowledge the car has not been in Germany. My only thought is that it may not be running the original ECU, which brings me to my next question... can my ECU be changed for an ECU from an identical model to avoid main dealer charges?

 

Regards,

 

Will

 

If you are talking 2.3, the standard set up is indeed 95 octane. The PCM is recalibratable for 91RON, as some markets where the Galaxy was sold (eg. Germany) still sell the stuff. If yours has been reconfigured for 91RON, it does beg the question why, as it isn't sold in the UK. Was the car previously used in Germany?

 

It certainly won't be the cause of your poor running - the codes tell you that the lambda sensor is faulty, or at least the wiring to it is - so is 99% sure to be the cause of that, but the retarded ignition timing for 91 RON will make the car less responsive at lower engine speeds and not help the fuel economy either.

 

As far as I know though, getting the PCM reset to 95RON requires WDS or IDS at a main dealer.

 

George.

[seatkid]

I'm inclined to think your problem is the lambda sensor (aka oxygen sensor) - this is a common failure. If you replace this you MUST get the correct type (OEM) as "universal" types dont work in this application.

 

I also suspect the ECU has automatically reverted to low octane setting in an attempt to resolve the issue. In any case I wouldnt trust anything a garage told me and certainly wouldnt go changing ECUs without lots of corroborating evidence.

You might find that changing the lambda sensor and disconnecting the battery (to reset the ecu) is all you need to do.

 

ECUs very rarely fail.

[seatkid]

Oh...and before you change the lambda sensor, check fuse 26 (5A) - this supplies the sensor with power to pre heat it.

 

nb Fuse 26 on pre 98 models - different fuse on later models

Edited November 29, 2009 by seatkid