Has anyone replaced the Lambda / O2 Sensor themselves ?

gmetcalf

Member
Camberley
Hi All,

I filled up at Tesco, and 10 miles down the road my "Engine Emissions" light came on. Ideling has been seeking by a few rpm for the last week or so. Some reports say Tesco have bad fuel, others say its just one of those things.

I have a 56 plate 2.0 Z4, im very hands on and try to do things myself. However this is by far the most expensive car ive owned to date and dont fancy breaking it :-). Ive changed O2 Sensors on previous cars ( MX6 ), and managed to use generic 4 wire sensors. These are about £20 a pop, as opposed to the dealer charging £160 odd .....

So the question being has anyone changed theres with non dealer parts, and specifically has anyone tried the generic 4 wire part ? I assume the light will go out once the ECU detects "better" readings ?

Any advive ( particualry and schematics ) of how best to get access to the sensors and if there are any tricks to getting them out appreciated. ( There usually just a simple spark plug style fit ... but you never know :-)

Can anyone also confirm there is only one "front" sensor on the 2.0 ?
Thanks in advance,

Gareth

( PS - Ill put together a how to once its done )
 
When you say the emissions light is that the one that looks like an engine. If so, mine came on yesterday. I think it is related to the O2 sensor as I have a K&N and I think that is screwing around. Getting the error codes read on Tuesday anyway.
 
Yes - I thought it was the engine check light at first, but the manual says otherwise.

As a note - It looks like the 2.0 uses a 5 wire sensor :(

http://www.lambdasensor.com/main/bosch/price.pl?item=0258007142

£75 for a generic and £105 for a Bosch

http://www.eurocarparts.com

Have the Bosch for £77
 
I'm sure they are just past the first set of cats on the downpipes. But going off e46 layouts. Doubt they will have changed it. And there are normally 2 more cats after the downpipes.

Loads of room in the engine bay, so would have thought it would be easy to get to! Yeah right lol
 
Thanks Chris, Its still not stopped raining, so ive not maanged to have a look yet. I also expected there to be one pre cat and one post cat, but from initial research the 2.0 only has 1.

Is there an online manual anywhere - im sure ive spotted one on here befor but now cant find it :-(
 
Guys, got the error codes read today. The first time the light came on (about two months ago) it was triggered by the O2 sensor behind the cat. The second time (last week) it was triggered by the O2 sensor in front of the cat. The guy also said the exhaust had a slight blow in it, he was looking underneath the drivers seat section when he said this. Now question is, apart from the exhaust having to be fixed, is it simply two O2 sensors gone or is it a sign that the cat in on the way out :-(. The car is 2005 with 55K miles on the clock. Any help would be greatly appreciated.

Sean
 
seanodwyer said:
Guys, got the error codes read today. The first time the light came on (about two months ago) it was triggered by the O2 sensor behind the cat. The second time (last week) it was triggered by the O2 sensor in front of the cat. The guy also said the exhaust had a slight blow in it, he was looking underneath the drivers seat section when he said this. Now question is, apart from the exhaust having to be fixed, is it simply two O2 sensors gone or is it a sign that the cat in on the way out :-(. The car is 2005 with 55K miles on the clock. Any help would be greatly appreciated.

Sean
Could it just be the exhaust blowing that is causing it, I'd get that fixed as a first step before doing anything else. Can the O2 sensors be tested to check they are working properly?
 
Thanks for the schematics, finally got round to checking it out. Mine has a 5 wire front and 4 wire rear sensor.

Does anyone know if the Emissions light will go out when the sensors are changed, or if you have to get it reset ?

( If it needs to be reset im trying to decide between the cheap ELM327 ( £15 ish ), mid range CReader V ( £50 ish ) and the relatively expensive Peake R5 ( £125 ish ) )
 
Yeah I think you'd need to try and see, I think it would go out, although it might leave a fault code that would need clearing next time the car was serviced.
 
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