o2 sensor.....halp please :(

[jinjur]

Hi all,
Well, recently the Clio had been throwing a P01030 intermittently which I read as being "O2 Sensor Circuit (Bank 1 Sensor 1)" and I understood that this was the front O2 sensor (Ph2 172)
So I grabbed one from ECP (A HAAS one might I add, not Bosch) and dropped it in. Pig of a job, but done nonetheless.
So, for about a week I haven't seen the EML so I was happy all was well but did notice an occasional splutter.
Today however, the EML came back on and as soon as I got home, I plugged in the RSTuner to see what was what and I will be honest, I am a bit confused/worried.....was hoping you could give me some thoughts or pointers?
So firstly, I read the codes and saw the following:

And then I decided to do a live trace of the O2 sensors and see what was what:
Ignition just turned on and I can see the front O2 sensor ramping up, which i thought was odd:

Ignition still just on and it settles like this:

So when I start the car this happens, front O2 starts to drop:

Eventually settling like this, flat. I thought this should be pulsing?:

When I raise the RPM, The rear O2 climbs like this but front still flat:

Does anyone have any ideas?
I had hoped that when I replaced the front O2 the car would feel, I dunno, more peppy......but it didn't feel different at all.

Would you guys expect the above to make my car run bad and have you any thoughts for me?

As always, appreciate the help
J

 

[Amos91]

Try swapping the front & rear lambda around, will help eliminate a fault with the new sensor.

 

[jinjur]

Try swapping the front & rear lambda around, will help eliminate a fault with the new sensor.

Will give that a go tonight fella..........sweating blood at the thought of pulling both sensors now

 

[jinjur]

Just nipped down to shop and EML came on more or less instantly

Can anyone confirm if the O2 (front) value should be a pulse in RSTuner?

A

 

[jinjur]

Actually, here was a reading from before I changed the O2 sensor.......this is the one that was supposed to be faulty

 

[green]

My elm light started to go on and off for a few weeks and then stayed on all the time. Changed the front o2 sensor..light stayed off for a few days then went back to staying on. There doesn't seem to be any performance problems just the dam light! Could it be down to the cat ?..mines only done it since putting a sport cat in.

 

[jinjur]

Eugh......now its doing this

 

[jinjur]

And now................wtf

 

[jinjur]

This has to be bucked

 

[jinjur]

And it reeks of petrol while sitting here idling and watching it :/

 

[Amos91]

Switch to check then get a Bosch one. Only around £60 with discounts on ECP.

 

[jinjur]

Switch to check then get a Bosch one. Only around £60 with discounts on ECP.

I will try. I will be returning this part to ECP too and will bring the readout from it. I hope that is enough.

 

[Amos91]

http://www.carparts4less.co.uk/search/710745577

Discount code - SAVEME75

 

[GrahamS]

OK, so. I'm no expert but it looks to me like the lambda is functioning correctly. It's just switching between closed loop (where the ECU uses the narrow band lambda sensors reading) and open loop where it uses preset values. Usually open is under acceleration and closed for idle, light acceleration and certain rev ranges. I think the ramping up you're seeing is the warming of the lambda sensor.

The lambda could be throwing a fault because the mixture in the engine is incorrect and therefore the narrow band reading is constantly reading at the maximum or minimum values. The smell could be the cat, that usually smells of sulphur. Check your injector resistance values. I recently had a problem where I had an unhealthy injector, causing the mixture to run rich or lean (not sure which) but it wasn't bad enough to throw a flashing EML or misfire code, just the lambda code.

Do it like this, the reading should be 14.5 ohms when the car is stone cold and hasn't been driven for hours and hours. Leave it overnight before testing it. The pic shows which injector of mine was busted. I also pulled a plug and this one was sooty, implying rich running. The car wasn't running great!

Anyone please correct me if any of the above is in accurate, it's my experience but I'm not a mechanic.

 

[jinjur]

Jeez. Well that is throwing something else into the mix now
Do you think it is worth me pulling the lambda tonight then and putting the old one back in to see if it behaves similarly then?
Not going to get a chance to do the cold engine thing till the weekend as this is my daily steed.
Is that deffo normal lambda behaviour then? I have never seen a flat 0v reading on my front O2 sensor before.
J

 

[GrahamS]

The injector test is easier to do that swapping the lambda so I'd wait until the weekend, test those and if one isn't obviously on the waft then swap back the lambdas and do a back to back comparison.

I'm not 100% sure about the lambda behavior but when on open loop the lambda isn't in use so logic says it doesn't do anything and isn't being asked to by the ECU. Google would be better than me on that!

 

[jinjur]

Makes perfect sense bud......I can't be rational at the minute (blind panic) so appreciate well grounded and sensible approaches such as yours and Amos.
Will wait till I get a cool period and test the injectors and take it from there.
J

 

[jinjur]

Ok.....well......I am sort of figuring that it is as cold as its going to get tonight, being nearly 20 degrees and all..........I also suppose I am looking for an injector standing out as being different rather than a global change.

So checked the resistance on all 4 injectors and they all.....showed 15.7 Ohms.

That sound about right?

J

 

[jinjur]

Well.......I swapped them.........obv a temporary solution given the different cable lengths so a bit of a botch for now.
But, no EML light......and after a fairly heavy hoking......same as before, but the O2 graph looks like this

 

[Amos91]

Not quite following, are you saying the EML light came back on after swapping? If so is it still bank 1 sensor 1?

 

[jinjur]

Sorry, just read it back......made no sense.
I pulled the HAAS sensor as I have no confidence in it given the lack of movement in its values.

I put the original one back in but swapped it with the rear O2 (which was basically fused to the cat might I add). So right now.....both original O2 sensors in but swapped position and the results are as I posted above.....with no EML light.

I am pretty confident that the HAAS one is borked. Was doing some internet reading (dangerous) and the O2 sensor should definately be showing a sine wave at idle which it wasn't. The old sensors seem to follow proper behaviour (sine wave at idle and constant running with the front O2 going flat at WOT).

I think if there was an injector problem causing rich/lean running......it would have affected the old sensors the same which does not seem to be the case.

Does that make sense and if so, is it common for after market lambdas to be so badly wrong or faulty?

J

 

[Amos91]

To be honest I do not much about HAAS but everyone on here recommends replacing with the Bosch unit.

 

[jinjur]

I know mate, never heard of them myself but there was a marked price difference which tempted me.........the downstream lambda was replaced with Bosch a few years ago.
I should have known better.

 

[Amos91]

I know mate, never heard of them myself but there was a marked price difference which tempted me.........the downstream lambda was replaced with Bosch a few years ago.
I should have known better.

Just got this through in case its useful.

Search ECP for 710745577.

Use FLASH25 for discount (most stores seem to have one for click & collect).

Then return the old one.

 

[jinjur]

cheers bud, you are a legend

 

[Amos91]

Ends at midnight!

 

[jinjur]

Reserved to collect today hopefully :smile:

Different branch that I bought the faulty one from though......hope there is no grief about that

 

[jinjur]

Well......different branch would not accept the return so I reserved the part for the original store and it should arrive in today.
A