I have a BA MkII XR6 that has done 120,000km's... It uses on average 13.5L/100km's.

Ive been told that if I replace the o2 sensor, this should make my fuel efficiency improve.

What I would like to know is:

1. Is this true?

2. Do I actually need to replace it???

3. What is a o2 sensor?

If you want fuel economy ...........

buy a Yarris

An oxygen sensor is a sensor which is placed in the exhaust to measure the oxygen content of the spent gases, The ecu will adjust injector on time to acheive the correct air fuel mixture based on the signal that the o2 sensor reports.

With age they get slow and produce less voltage which the ecu reads this as a lean situation and makes the injectors spray in more fuel which will mean you are acyually running richer than what is being reported.

If you want fuel economy ...........

buy a Yarris

HOHOHOHO!! It's spelt "Yaris", comedian.

An oxygen sensor is a sensor which is placed in the exhaust to measure the oxygen content of the spent gases, The ecu will adjust injector on time to acheive the correct air fuel mixture based on the signal that the o2 sensor reports.

With age they get slow and produce less voltage which the ecu reads this as a lean situation and makes the injectors spray in more fuel which will mean you are acyually running richer than what is being reported.

Thanks man... having done 120,000km's and it being only 5 years old. It shouldn't really need replacing, should it?

It's about the age where it could be faulty, but there are a host of things which can lean to it failing prematurely.

Thanks for the info Ratter, so how much to replace the o2 sensor for a BA/BF? and who do we go to to do the job

A decent brand may cost you $100-150, If BF only the pre cat 1 may need replacing, it is something you could do yourself if handy with some tools or your mechanic should be able to do it for you

Edited February 21, 201016 yr by ratter

easy to do just take the heat shield off and un plug and un screw took me bout 25 mins

Genuine from Ford are about $450!!! I got an aftermarket one for $90 from a ford member on another site - pm if you want to know more. I only replaced my first one (I have a BF) as I will get the second one turned off when I get it tuned. Has made only a very small difference to my economy but I think that's more because the second one is giving all the funny readings due to the high flow cat.

Once I get it tuned I would expect my economy will be better

Cheers

Phil