Pre cat lambda fault

[lee24]

Hi, i had a faulty pre cat lambda sensor so i replaced it about 2 weeks ago with a bosch 1. It ran fine until 2 days ago and the symptoms began to show again, then the eml light came back on. Exactly the same fault came up again so cleared the code and it keeps on coming back.
Ive had a look at the leads to the sensor and they look fine.
Could it possibly be a dud sensor from bosch ? Or could something else be causing the problem ?
Any help or suggestions much appreciated, cheers
lee

 

[Dan@M.A.D]

Get a Lambda extender.

http://www.ebay.co.uk/itm/LAMBDA-02...arts_Vehicles_CarParts_SM&hash=item1e70838b45

 

[lee24]

Cheers for that, ive just ordered 1 ! Glad you dont think its related to something else!
Thanks, lee

 

[Dan@M.A.D]

Cheers for that, ive just ordered 1 ! Glad you dont think its related to something else!
Thanks, lee

It could be something else though! , Worth a try.

 

[lee24]

Hmm Hope not , this is definatly worth a go though. Cheers

 

[Dan519]

don't use one of those extenders on a pre-cat lambda, they're for tricking the ECU when you de-cat by limiting the gases the post cat lambda sees.

Codes don't tell you much, you need someone who understands the live data of diagnostics to see what's going on

 

[lee24]

Ahh rite ok, i'll have to get it looked at properly then. Cheers for your help

 

[lee24]

Bit of an update - i had my mate plug my car in to have a look at the live data.
The graph was all over the place when you first start it and then is fine when warm . He thinks it could be related to my temp sensor and he thinks its causing it to over fuel.
Took the 02 sensor out and it was black after only 3-4 weeks.
Has anybody come across something like this before ?
Cheers

 

[lee24]

Think this has now been fixed after changing the coolant temp sensor been a couple of weeks now and is still running fine !

 

[KevF182]

Think this has now been fixed after changing the coolant temp sensor been a couple of weeks now and is still running fine !

Nice to have the update, Thanks.

I'm probably going to swap my coolant temp sensor for peace of mind as my emmissions light has flashed briefly a couple of times recently, though could be any number of reasons of course. Car seems to be running fine, but MPG during warm-up phase is suddenly poorer than it should be and I'm guessing it might be something like this - my pre-cat O2 is relatively new too.

Did you notice a symilar symptom?

 

[lee24]

No problem, after i changed it the car warmed up a lot quicker which is nice. And yeah my mpg seemed to be suffering before i replaced it ! Its worth changing anyway i only paid something like £12 from gsf and took about 5 mins to fit !

 

[KevF182]

No problem, after i changed it the car warmed up a lot quicker which is nice. And yeah my mpg seemed to be suffering before i replaced it ! Its worth changing anyway i only paid something like £12 from gsf and took about 5 mins to fit !

My thinking too. No substitute for proper diagnosis but it can't hurt. It's one of the few things that hasn't been done in the last 50k - I like prevention and peace of mind

 

[clioalbania]

are they standart lambda sensors or every make has its own?

for example can i try an oxygen sensor from a vw , or they have different pins ?

or can i clean it , there is a way how to clean or repair it ??

thanks

 

[lee24]

I'd imagine they would all have different plugs and lengths of the lead, but dont know for sure.
I took mine out and gave it a blast with a compressor and some brake cleaner and it made no difference.