95 Gems now with O2 sensors

[FANTOM P38]

Hi Guys,
Just fitted set of O2 Sensors to my 95 P38 4.6L Gems today!
Hoping someone on here has done this before & can answer my question.

I'd like to know if what needs to be done if anything to engine ECU or & BECM to tell them these are now fitted so engine can compensate for readings being sent to it?????? Hope this makes sense. Someone told me need to upgrade ecu SOFTWARE! I would like to know if this is necessary or is there just a setting that can be changed in BECM via Rovacom or similar.

[TheTree]

Hi

As far as I know you don't need to do anything, but you can do a reset so the adaptive fuel trims are derived from a default setting

Regards
Steve

[Rupert Prior]

you cannot change the o2 sensor configuration in the ecu. check the code number on the ecu to find out what type you have, but a no o2 ecu will not take any notice of the sensors. don't reset the adaptions on a no o2 ecu unless you can perform an open loop tune, as it will run rich until you manually lean it out.

[rangerdanger]

I looked into this myself for my 95 a while back and come to the conclusion that the only way O2 sensors would give benefit was to fit a Mark Adams 'Tornado' chip as well. The chip supposedly will recognise the sensors.




I never got around to doing it, too many other things to spend $ on first.

[BusinessConnected]

Yes:
You need to fit a Tornado chip to enabled the O2 Sensors to work... I have done it to one of my P38s which was on LPG...

Fantom:
If you are keen I have a Mark Adams Tornado chip which I haven't fitted/used as yet... I can give you a decent discount on a New one if you like... Just Reply or give me a PM....

[rangerdanger]

Hmmm, if Fantom isn't, I could be......

[davidsonsm]

Martin,

Assume you had to get bosses welded in to the exhaust? And what did you plug the O2 sensors into?

[FANTOM P38]

PM Sent

Hi Sean, I had bungs welded to exhaust system for o2 sensors. the wiring is already provided as standard just need to have computers pick up the addition of sensors but seems bit more involved that i first thought.
will let you know outcome.
Still working on P38 BBQ at my place sometime soon hopefully just got find the right weekend when no work on!

[DT-P38]

you cannot change the o2 sensor configuration in the ecu. check the code number on the ecu to find out what type you have, but a no o2 ecu will not take any notice of the sensors. don't reset the adaptions on a no o2 ecu unless you can perform an open loop tune, as it will run rich until you manually lean it out.

Are you sure Rupert? I am sure someone on here has added and livened sensors in a Gems. Didn't other countries have them? Surely there is a relatively cheap and easy way to make it all work?

[TheTree]

Hi

As far as I know, what has been said here is correct, the only way to get the system to see the newly added O2 sensors is to fit the tornado chip, not a cheap option though.

Just a thought, it may be possible that you could fit a later model GEMS computer to your vehicle, others would know if that is feasible or if it is tied to your VIN in some way.

Regards
Steve

[FANTOM P38]

Well it seems that I may be able to flash my existing ecu with program from later model unit!
Am likely to give this a shot first otherwise change ECU
Thanks for help guys.

[FANTOM P38]

Just thought I'd post an update to this thread for anyone contemplating this mod.
All working fine now after installing O2 sensors all that was needed was to swap out Gems ECU for one from a 1998 model. input vehicle details i.e. Vin S/N etc via Rovacom and Bobs your uncle!

ps did try to flash original ecu with software from later one but did not work so I guess I'll keep that one as spare, just in case.
Hope this helps anyone else considering same job.

[mtb_gary]

Has the fuel consumption changed at all since installing the O2 sensors and ECU?

Gary

[FANTOM P38]

Well Gary, I dont know as I dont drive it much probably only done 50ks since done so guess I'll have to wait & see.
From what I understand it may take a little while for it to adapt to new values.
So once i know for sure will post up findings.