Pesky CEL's

carl_evs · May 8, 2007, 12:56

Well, had a problem with P0141 a couple of weeks back. Got a generic sensor from Gendan - spliced it in - bye bye light.

Whilst I had it out I also changed the exhaust and gutted the precats (which were in perfect condition actually - no need to worry about any potential damage!!)

Now heres where the fun begins.. the exhaust sounds like it's blowing...however used all new gaskets etc when fitting..even used some of the assembly paste stuff just to make sure. Also you cant hear it when idling or blipping the throttle, had my brother down there feeling for leaks whilst i was in the pilots seat!! It only seems to do it under load (i.e when driving). It may just be its natural sound but it doesnt seem right to me.

Also in the last few days its throwing CEL's for all 3 sensors... although this is intermittent - I can reset them and take it for a good long thrash and it's fine sometimes...others up they pop. I know when i had the initial one go it came back straight away when reset! Also ..i was extremely careful when removing the sensors - not worried about having damaged them as am used to working with fragile materials.

Anyone have any ideas.

P.s Also tried different settings on Unichip, one map seems to ba a little better than the other?!

kanujunkie · May 8, 2007, 17:11

unichip will do nothing unless theres an intermittant connection of course or its completely knackered. As for the CELS well do you also get a message for the EVAP system as well? if so its a dodgy fuse on the LHS of the engine bay, one of the 7.5amp ones thats marked up as EFI2, try changeing it anyway

BenF · May 8, 2007, 17:21

Hmm, CELs and blowing exhaust may be related as the readings from the O2 sensors won't tally with what the ECU is expecting.

For all three to be going, there must be a problem between the engine and exhaust manifold. The way you describe it though, only blowing on load makes it sound like a small leak.

carl_evs · May 9, 2007, 12:49

Well i had a new one last nite... none of the o2 sensors threw a CEL, instead i got P0125 - insufficient coolant temp for closed loop fuel!!

I know what you mean about a leak round the manifold possibly causing the 3 sensors to act up...have disconnected and reconnected it twice now (along with addition of paste) and cant find the problem. Dont think i would be able to persuade anyone to hold onto the back so i can recreate the conditions i'm getting it at - i.e under load (driving)!!

It never rains eh?! Anyone?

kanujunkie · May 9, 2007, 14:26

give the ECU a reset, sounds like its playing up

aaronjb · May 9, 2007, 15:09

Indeed, or possibly a wiring fault? Common earth on all those sensors maybe, something along those lines..

kanujunkie · May 9, 2007, 16:37

they do indeed have a common earth

carl_evs · May 10, 2007, 11:00

Ok, will reset the ECU anyway as thats a doddle.

They all have a common earth eh, where is it located?...will disconnect and make sure theres good contact...can also trace back and see if I have any problems down the line!!

Thanks for advice guys.

kanujunkie · May 10, 2007, 14:26

not sure on that, i can post up the wiring diagrams tonight if you want

carl_evs · May 10, 2007, 16:39

If you would matey please...gonna have to get my work head back on!!

kanujunkie · May 10, 2007, 19:42

m http://www.stuandele.co.uk/mr2roc/enginecontrol.pdf m

carl_evs · May 26, 2007, 16:11

Right... after having the manifold etc off and refitting with generous amounts of hylomar, the o2 sensors are no longer lighting up the CEL.

Unfortunately i'm now getting P0443 EVAP Emission Control System Purge Valve C Fault.

Anyone... evrytime I seem to get rid of one, up pops another!!

Checked the earth and it seems fine (Engine block LH??), no corrosion etc making it a bad earth.

kanujunkie · May 26, 2007, 18:14

its the fuse, look in the engine bay, left side theres a fuse box there, inside there are 2 fuses in there that are 7.5amps, one of them is marked EFI2, replace that and the messages should clear

carl_evs · May 30, 2007, 10:36

Cheers Stu, it did the trick......... for 2 days anyway!

Now i'm back to the original P0141. I do not have the expletives to say how i feel!!!

Am hoping that it's just a bad connection in one of the crimps on the new sensor i put on (closes eyes and prays) as there is a bit of vibration at the moment in the exhaust as dont have the hanger for the second pipe mounted yet- brackets in the post - and its vibrating against bits at the back of the car. Really annoying too!

If not, looks like another sensor s:(

s:(

aaronjb · May 30, 2007, 10:44

Check the resistance of the sensor - I checked Ross' last weekend and it bells out to 4.5Ohms, the second replacement he'd got was 4Ohms - my suspicions (based on what someone else posted in another thread) is that the power draw is making the ECU think the heater is shorted out..

Standard resistance is ~14Ohms - or rather, was on Ross' two original manifold O2s.

If you're using an ebay sensor it might be worth sending Gendan an email to see what the resistance of the heater circuit on their generic 4-wire Zirconia sensor is?

[edit] Because I'm nice like this, I mailed Gendan for you s;)

s;) Here's their reply:

Quote from: "Gendan"The universal sensors all have a resistance of around 4.5 - 5 ohms. Toyota and Honda tend to tweak a lot of their sensors to increase the heater resistance, and so those cars aren't really compliant with the universal sensors. We do sell direct-fit sensors for a lot of them though, which have the relevant resistance.

Which is interesting to know s:)

s:)

Of course, the direct-fit's are expensive (though slightly less so than Toyota):
m http://www.gendan.co.uk/product_LB1578.html m

carl_evs · June 1, 2007, 12:46

Right, thanks for e-mailing them for me!!

Hmm, interesting. Not using an ebay one, did get a generic from Gendan.
Will have to get the multimeter on it at the weekend and see what it's doing.

Anyone else had any problems with the generic ones from Gendan.
Did do a good search on them at the time and dont seem to remember anyone having problems with them - although I am probably wrong.

As for price, they are rather costly!!

Wabbitkilla · June 1, 2007, 12:54

Quote from: "carl_evs"Anyone else had any problems with the generic ones from Gendan.
Did do a good search on them at the time and dont seem to remember anyone having problems with them - although I am probably wrong.

As for price, they are rather costly!!

Yes - absolutely, it would've been nice for them to make that statement before i bought their generic sensor for Toyota / Honda engines!! That's just not nice. I get P0141 when starting warm - reset it and i'm ok for the rest of the trip. From cold generally not a problem - but not always.

And that price s:shock: :shock: s:shock:

I will do a bit of searching for an alternative.

Thanks for posting this up guys - i am not going mad after all! s:roll: :roll: s:roll:

I've found that "Walkers" do a direct replacement sensor, their code is 250-24360, busy finding places that sell them now.

Looky look here
and here

A rather useful page- here

Which means the part code for the one after the cat is 250-24404, it appears Jaguar use the same one!

Don't seem to be having any luck getting the US places to sell across the water, so trying these guys now.

Another chart telling us about options here

aaronjb · June 1, 2007, 14:16

Let us know how you get on with that s:)

s:)

It seems that it's rather luck of the draw whether the generics will work or not - some peoples ECUs are perfectly happy with a low resistance, while others aren't.

You could, of course, fit a wire-wound resistor in series with one of the heater leads, which would increase the overall resistance to a point where it doesn't pop a CEL.

Wabbitkilla · June 1, 2007, 16:17

Ok how does around $120 sound?

Look here, does it look familiar and even comes with the cable clips?

carl_evs · June 1, 2007, 18:21

Wabbit, if you need one and are happy to wait a couple of weeks i can get them shipped over for nothing - altough may incur tax.

My head office in the Us will receive them and either send them with the weekly load or my US boss will bring them with him when he flies over on the 24th.

Might save us messing trying to get a company to mail overseas.

Edit: Looking on one of the links - Rockauto - there is a beck/arnley one at $80 with clip. Just over 40 quid and no splicing. Looks like the one for me. Will hold off and see what you want to do!

Wabbitkilla · June 1, 2007, 20:32

That'll be this one then
Linky

Yup - i think i'll order that - note they sell MAFs too

Wabbitkilla · June 10, 2007, 12:14

I received my new O2 on friday, and although it doesn't have the Denso markings, all wiring and plugs match the OEM sensor.

Checked the heater circuit and 16.5 ohms recorded.

That's as opposed to the generic one sold by Gendan which measures at 4.9 ohms.

I'll let you know if it performs properly.

carl_evs · June 11, 2007, 08:58

Please do!
Will order one if they do the trick!!

Ernie Ball · June 12, 2007, 16:00

Not to hijack this thread (I'll start a new one if I'm told) but:

my car just threw a cell today. I'm off to the US on Thursday and can't get it serviced beforehand. I don't have an OBD II reader.

Anyone have any suggestions for things to check? The car is running perfectly, as far as I can tell. I've checked obvious things like hoses and wires to the limited extent of my knowledge. I'll reset the ECU now.

What are the kinds of things that could trigger a CEL without any obvious symptoms?

MR-S · June 12, 2007, 16:56

Looks like another O2 sensor.
I'm waiting on my OBDII reader to arrive at the mo. I'm also waiting on my O2 sensor to arrive from Toyota.
I bought a generic 4 wire one, fitted it and it works until the engine gets to normal running temp. Then it throws the error again. Looks like the generic just doesn't sned the correct readings when the exhaust gas gets hot. So I've gotten a mate of mine in a garage to order one from toyota at trade price.