O2 sensor fault and lacking power 4.4 petrol 2004

Not a major drama but i have a couple of fault codes on my all comms under the M62 engine module section, 'o2 sensor heater circuit bank 2 downstream sensor fault' and also o2 sensor circuit bank 2 downstream sensor fault' both saying last occurrence maximum signal. i have cleared them and they come straight back.

Is this as simple as replacing the sensor, i think its the passenger side nearest the back of the car. The wiring looks fine that i can see.

i have also been sensing a slight misfire or slight lack of power recently under load, tick over is fine and steady.

i haven't changed the plugs or filter since i have had it which is 5000 miles or so so wondered if that may need attention although when i got it they had supposedly just been changed.

Any help much appreciated as always.

Hi Andy,

I always get the 'o2 sensor circuit bank 2 downstream sensor fault last occurrence maximum signal.' fault too, and returns immediately also.

It has done it ever since I have had the car (June 2012) with no ill effects.

You seem to have an additional fault - Sensor Fault - which I don't get on mine so maybe that is indeed a true fault.

Changing the Filters, fluids and plugs would be a good start...I tend to notice a hesitation/ever so slightly rough running at just over 50mph but beyond 60 she smooths out again....most odd!

Oh the joy of V bloody eights

Saint.V8 said:

Hi Andy,

I always get the 'o2 sensor circuit bank 2 downstream sensor fault last occurrence maximum signal.' fault too, and returns immediately also.

It has done it ever since I have had the car (June 2012) with no ill effects.

You seem to have an additional fault - Sensor Fault - which I don't get on mine so maybe that is indeed a true fault.

Changing the Filters, fluids and plugs would be a good start...I tend to notice a hesitation/ever so slightly rough running at just over 50mph but beyond 60 she smooths out again....most odd!

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Cheers Ant,
i may give it a change, i too had the same fault since i had the car as you have but i now have the extra one but i could do with giving it a service.

like you say i dont notice much and it idles fine and revs up fine but just feels a little reluctant, almost like a brake is binding on but the engine sounds a little rough too.
Do you have any preference on plugs and is it an easy job to get to them?

Dont forget i got my all comms here if you want to try it one week mate

cheers

Datatek said:

Oh the joy of V bloody eights

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i know what you mean i used to love driving tractors as well

I've had similar faults. I changed all 4 sensors and the maf sensor. Also the pcv valve plus breather pipes. Also had an airleak on the inlet pipe from the air filter were it joins the in let manifold. All sorted now!

v8hotrodboy said:

I've had similar faults. I changed all 4 sensors and the maf sensor. Also the pcv valve plus breather pipes. Also had an airleak on the inlet pipe from the air filter were it joins the in let manifold. All sorted now!

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i am also a fan of changing everything related and i had already changed the vacuum pipes and the breather pipes when we did major surgery last year but i didnt change the PCV valve or MAF sensor.
i think i will change the offending o2 sensor and see what happens
cheers

I got some genuine bosch ones that are universal 4 wire ones. Just cut and solder your old plugs on. Ebay £17.50 each. And got a used maf from range rover breakers ( member on here I think) don't use a non genuine one even a new one, mine had one fitted and it was crap!

v8hotrodboy said:

I got some genuine bosch ones that are universal 4 wire ones. Just cut and solder your old plugs on. Ebay £17.50 each. And got a used maf from range rover breakers ( member on here I think) don't use a non genuine one even a new one, mine had one fitted and it was crap!

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i just ordered this one which i am hoping is correct, i have also got a new battery which is always a drama as my immobiliser normally loses its code when i disconnect the battery which is a total expensive pain as it has to go to main dealer on a trailer or they come to me with a laptop.

Genuine BOSCH 2003~2005 Range Rover Rear Oxygen Sensor MHK000220 | eBay

RANGE ROVER BOSCH UNIVERSAL 4 WIRE LAMBDA SENSOR OE QUALITY 12 MONTH WARRANTY | eBay

This what brought

I get it now, just solder the old plug on?
Would it be coincidence but my range been running crap since i put in morrisons petrol for the first time as always used esso before
I ordered some Bosch super 4 plugs as well if anyone knows what they are like?

Bmw forums say crap fuel makes them run rough

holidaychicken said:

I get it now, just solder the old plug on?
Would it be coincidence but my range been running crap since i put in morrisons petrol for the first time as always used esso before
I ordered some Bosch super 4 plugs as well if anyone knows what they are like?

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Petrol is petrol they all buy off the same suppliers - the only difference is the additive packs.

Standard NGKs are the best plugs - good value and they're rarely duff - I've had plenty of duff Champions and Bosches over the years. Years of running finicky two strokes soon tells you what the best plugs are!

v8hotrodboy said:

Bmw forums say crap fuel makes them run rough

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strange its been fine for 5000 miles and then as soon as i put in morrisons fuel its rough.
i'll replace the plugs, check the airfilter, replace the sensor and see whats its like and if its still a bit rough i'll run it low on fuel and put in some esso again
thanks for your advice

StuckAgainSteve said:

Standard NGKs are the best plugs - good value and they're rarely duff - I've had plenty of duff Champions and Bosches over the years. Years of running finicky two strokes soon tells you what the best plugs are!

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i have a 1988 yz80 and i have had an NGK plug in it for ages and never missed a beat, oh well the bosch super 4's are on their way so will report back if it goes like the delorean from back to the future when they are installed.

Do you know the code for the standard NGK plug please ?

holidaychicken said:

do you know the code for the standard ngk plug please ?

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bkr6equp

holidaychicken said:

strange its been fine for 5000 miles and then as soon as i put in morrisons fuel its rough.
i'll replace the plugs, check the airfilter, replace the sensor and see whats its like and if its still a bit rough i'll run it low on fuel and put in some esso again
thanks for your advice

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personally I don't/wont use supermarket fuel anymore,strangley I get more mpg on more expensive fuel & smoother running,there is a difference imo.with morrisons fuel I used to get the eml on quite often very rare now always read 02 sensors aswell

StuckAgainSteve said:

bkr6equp

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thanks mate

wil2813 said:

personally I don't/wont use supermarket fuel anymore,strangley I get more mpg on more expensive fuel & smoother running,there is a difference imo.with morrisons fuel I used to get the eml on quite often very rare now always read 02 sensors aswell

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i dont think i have an engine management light that works as most people that have o2 sensor fault has had EML on, but i have never seen mine, how could i check and where is it?
cheers

holidaychicken said:

i dont think i have an engine management light that works as most people that have o2 sensor fault has had EML on, but i have never seen mine, how could i check and where is it?
cheers

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I get the same fault as you (minus the Lambda Sensor Fault) and I don't get the EML...

The EML is on the Left hand side of the instrument display...should come up as a check light when you turn the ignition to the second position...little orange engine looking symbol!