NCT Failure on emissions.

Horsey

Hi,
I have a customers car here in my garage after an NCT failure on emissions.
Its a 2005 peugeot 206. Just under 80k. (km)

The problem is at high idle.

The reading is Lamda 0.90 and co 3.68vol%

Now, after doing the basics for elimination purposes. Ie.Plugs air filter, fuel additive etc., and there was no difference.
So, new Lamda probe even tho it was giving a reading that it was working on my laptop readout.
No joy.
New catalytic converter.
No joy.
Getting desperate now.
New injectors in case one was stuck open.
No joy.
On to peugeot main dealer..Lovey helpful guy..
He tells me to, well, do what i did already.

I cant even go into full detail here what else I did to car as I dont have 3 hours to spare.
I have many friends in the business and after I rang them, they rang a friend and a friend of a friend.
Anyway, I was told this was the place to come for help, of which any is fully appreciated.
And before I go, The only thing that brought down the emissions was a good run along the M50 without using 5th gear.Sounds like it was trying to clear it out but only came down to certain point and stopped.
I did not want to post that bit as it might put you off the track.But someone was going to suggest it.

Looking forward to reading your opinions.
Thanks..

cadaliac

was it a new or second hand cat converter?

Seems like you have spent a lot of money already......

Horsey

All new parts Cadillac..

Nissan doctor

Why are you changing so many thing instead of testing them to check their functions?

What is the range and switching time of the pre cat lamda? And what reading is the post cat lamda giving.

Have you tested the lamda heating circuit?

What is the base ignition timing?

Any evidence of oil consumption?

I worry about much the customer is being charged for your game of mechanical pin the tail on the donkey.

Horsey

@ Nissan doctor..
Dont worry about cutomer costs..
I will be soaking most of that up, including lamda probe and cat.
Im not in the business for money, more worried about getting car right.
Anyway, all parts were tested and are reading ok.
I just wanted to be 100% sure as I was not getting anywhere by taking sensors off, testing them, reading ok and putting them back, so i decided to replace them in case i got a false reading.
Only thing i can say is the sensor 2 bank 1 is working as hard as sensor 1 bank one, which is not correct, and would indicate raw petrol going into cat.
I stand to be corrected on any of these points, as I feel in my haste I might have missed something simple.
And as i said previously, if i had not have done so already, I most likely would have done on main dealers advise. (fit said parts)
Thanks.
PS..been in the business for near 40 years..But something always pops up to keep you on your toes..Think this is one of them.

Nissan doctor

Horsey wrote: »

@ Nissan doctor..
Dont worry about cutomer costs..
I will be soaking most of that up, including lamda probe and cat.
Im not in the business for money, more worried about getting car right.
Anyway, all parts were tested and are reading ok.
I just wanted to be 100% sure as I was not getting anywhere by taking sensors off, testing them, reading ok and putting them back, so i decided to replace them in case i got a false reading.
Only thing i can say is the sensor 2 bank 1 is working as hard as sensor 1 bank one, which is not correct, and would indicate raw petrol going into cat.
I stand to be corrected on any of these points, as I feel in my haste I might have missed something simple.
And as i said previously, if i had not have done so already, I most likely would have done on main dealers advise. (fit said parts)
Thanks.
PS..been in the business for near 40 years..But something always pops up to keep you on your toes..Think this is one of them.

What was the range and switching time of the the pre cat lamda though? As this will give you an indication of its function and the cars fuelling.

Also if the post cat lamda is switching and reading the same or similar to the pre cat, it means the cat isn't working, if its switching but at a lower range then the pre cat lamda then it tells you that the cat is working but the car is badly over fuelling.

If over fuelling is the problem you need to be looking at afm/map sensor readings, injector pulse readings, knock readings and checking cylinder pressure loss.

Horsey

@ Nissan doctor..
Thanks..
Some good information there..
I will carry out some more tests and come back with some anwers for.

Nissan doctor

smokie2008 wrote: »

Nissan Doctor why not suggest a test to be carried out?? The guy doesn't need a lesson in dealing with customers, seems he's pretty stuck and theres nothing worse than a head melter of a job like this imo.

I've asked him the results of the tests he already carried out, he says they are right but obviously something isn't if the car isn't repaired.

The results of the things I asked in my first post would be things that would effect emmissions/fuelling, so I was asking had he checked these and what the readings where.

crosshair1

I would forget about the cat and o2 b1s2 until you locate the problem, then you can address if the cat is up to the job.
Your Co is way high even if the cat is not doing anything.

Did you carry out a vacuum test at idle and high idle? did it correspond to live data?
I assume you have no fault codes yet??
Did you reset learned values after you have replaced the parts, this is available in Peugeot PLanet (not sure about other tools), what tool are you using?
You should also monitor long and short term fuel trims in eobd check what these are before you reset the learned values. these will indicate whether the ecu is trying to add or subtract fuel ontop of its calculation for what should be ideal.
Are you sure that you are running in closed loop and o2 b1s1 is actually switching, this i would not trust from serial data, multimeter or scope at sensor only.
I have had success before with software updates on petrol pugs with slow responding b1s1 o2 (should be last resort tho)

Horsey

Thanks guys..
I really do appreciate the help..

Just an update to all who are trying to help.
It seems that after all I have done I have been supplied with a faulty Lamda probe / oxy sensor.

Brought to the tech guys in peugot and they reckon that even tho its giving all the right readings its a faulty probe.. (Bought from Peugot)
I did not feel to bad about it when there was a crowd of "Master Technicians"
having a look at car and not finding the problem for a while.

I will have part at 12pm tomorrow..
I will come back and let you know.
Thanks.

Horsey

Just a final update on this car guys because you were so helpful..
Brought the car to a Peugeot main dealers and explained the problem to worshop service manager.
He never heard of the problem even tho had years of experience.
Some young mechanic (could have even been an apprentice) walked into the office and only got tail end of story.
I think there is a download for that problem he said. (For ECU)
After all the Peugeot guys I had already talked to (Including "the experts") nobody came up with that simple solution.
Lo and behold, youg fella puts it on computer, preforms a simple download from main computer and 20 minutes later problem was sorted.
Thanks to all for your help and sorry for taking so long to get back to you.
I was on holiday.