I just did a search & found 3 threads, but there did not seem to be an anser so..
My cats are gutted, my Lambda figure was 1.02 with a max permissable of 1.03 !
What would be a likely cause of this ??
Thanx
The main cat is knackered?
I certainly hope not s:( :( s:(
Could it be that the petrol is 'stale' - It's been in the tank for 4 months as the car has been garaged since August ?
PeterC
Just lambda? Or are other emissions out as well?
James
I've got this issue to sort out as well - the car is due an MOT (well, a while ago actually...) and I had an emmisions test done by my dealer when I was last there out of interest - it passed on the emmisions part but failed on the lambda test. My guess for me is that I am running rich for the turbo and only have a small race cat in place. For a stock N/A car I would say that it definately points to a poorly cat as the car if anything runs a little lean as standard.
can anyone explain exactly what a lambda failure is?
I understand teh emmisions particulates stuuff but lamda is rather confusing.
Quote from: "markiii"can anyone explain exactly what a lambda failure is?
In the tested conditions (I think it's warm idle, but it could be fast idle too) the lambda reading (taken from an exhaust sniffer) must be close to 1 (stoic, I believe - so 14.7:1 A/F).. I can't remember the lower limit, but it's quite a strict limit.
IIRC, E&OE etc
but was is lambda?
"Lambda Sensor" is another name for "O2 Sensor". They're one and the same.
that I kind of figured.
however a lamda failure isn't a physical 02 failure, since they aren't using our 02 sensors.
Sio I assume we are simpl;y refering to and overly rich AF Ratio as read by teh probe they shove up teh tail pipe?
in which case simply increase teh correction factor of the emanage so that it backs of teh injectors more? hence it will run lean?
Right. I didn't know crankshaft had an eManage.
shoot me now he doesn't
I read Slacey's post and got turbo sidetracked. s:oops: :oops: s:oops:
Quote from: "markiii"however a lamda failure isn't a physical 02 failure, since they aren't using our 02 sensors
Yeah, basically it means the mixture is off. But since the ECU uses to O2 sensors to make the mixture stoich, it probably means the sensors have worn down.
That's for a stock car anyway, once you mod it, it might be anything s:lol: :lol: s:lol:
Right, my MOT is tomorrow so I guess I will have to deal with this issue rather soon! Whether it passes or fails on the Lambda reading I will ask for some detail as to what the test is for and what it looks at so we will have a definitve answer.
Ian (mr-s_turbo), if you are reading this expect a phone call if I fail to get those tips you mentioned a while back s:wink: :wink: s:wink:
Hi;
Mine is Normally aspirated but unichiped & setup on a rolling road by millway 1 year (2000 miles) ago.
Here's the full set of readings from the crypton gas test done by kwik fit during the MOT yesterday:
Co Level---0.0 %
HC Level---34 ppm
Lambda----1.02
I have the performance curves from Millway but not the Emissions tests !
I have a feeling that my stale petrol may be a contributor ?!
PeterC
PS: Are the o2 sensors resistive ?? - could they be 'tweaked'
Quote from: "crankshaft"Are the o2 sensors resistive ?? - could they be 'tweaked'
They are actually voltage generators...but like any electrical stuff, you can alter the signal s8) 8) s8)
I'm here Sean, if you need me give me a call.
The problem when the lambda is high is definatly O2 related (if the cat is fine), i couldn't get mine to pass my first year turbo'd and in the end i swopped the 2nd O2 sensor that isn't used on my setup for the first, i also cleaned it with carb cleaner, and i got better results.
Now it's the wideband in, it is better but it has failed on the last 2 MOT's through high lambda. The way i get through is to reduce the amount of fuel with the e-manage but the problem is you don't actually remove any fuel, you increase the amount of air,as it's impossible to minus duty from the injectors. So the bloody CO level goes sky high and as the stock ecu kicks in trying to fight the emanage to get stoich, the fun begins trying to level out the CO and lambda within limits. You need a patient tester that will run a few tests as you play with the emanage to get the pass result.
This obviously helps no-one that hasn't got a piggy back ECU that they can alter fueling (or a flashy standalone eh Tem).
So from experience i can say if your lambda is high then try cleaning your O2 sensors, if no difference they are knackered or as said, the main cat is dead.
Quote from: "mr-s_turbo"Now it's the wideband in, it is better but it has failed on the last 2 MOT's through high lambda. The way i get through is to reduce the amount of fuel with the e-manage but the problem is you don't actually remove any fuel, you increase the amount of air,as it's impossible to minus duty from the injectors. So the bloody CO level goes sky high and as the stock ecu kicks in trying to fight the emanage to get stoich, the fun begins trying to level out the CO and lambda within limits. You need a patient tester that will run a few tests as you play with the emanage to get the pass result.
Looks like I'll be coming your way for tweaking advice too Ian s:wink: :wink: s:wink:
I'm up for MOT in 2 weeks, so popped in to have a chat with my friendly testers and a quick probe job today s:shock: :shock: s:shock: . At idle, my wideband gauge indicated good stability around stoich, and the MOT machine showed Lambda a shade over 1 (1.073).
But I tried a few rev ranges and can't find a point where both CO and Lambda pass. Seems to be one or the other.....B*ll*x!
The range for a "pass" on both CO and O2 seems very tight. I can't quite get my head round why a FI '2 with flat EManage maps would struggle compared to a N/A '2 under test conditions (closed loop idle). Can someone explain? Is it because of a less efficient high flow Cat?
Thankfully, my garage are happy to let me play around with settings (EM and Wideband analogue's switching point) until we can register a pass s:lol: :lol: s:lol:
It has to be the cat as nothing else is changed (that can affect the emmisions). That, and the MOT stations test equipment, how often are they cleaned and calibrated s:? :? s:?
It is strange how my WB shows stoich or slightly leaner, and the station says it's too rich, but i did try another station to see if it was their machine but got the same results, now i've got you lot going through the same so i know it's not my setup s8) 8) s8)
If you need me Ste give me a shout.
Just a quick blast from the past.
My old car failed on the Lambda (def o2 related) and there was leak in the gasket between the main cat and the H&S exhaust. Check those studs are tight and / or replace the gasket if necessary.
I had my MOT last night and I asked the guy what exactly the Lambda test was. He stated that the perfect reading was 1 (he did give the technical jargon name of the figure but I can't remember, but this equates to stoich) and that any reading OVER meant it was running lean and any figure UNDER 1 was running rich. This surprised me somewhat as I'd always figured that I would run rich, but it seems that both times I have had a test that as I was around 1.3 I am running lean.
Anyway, I didn't realise until I got there but the testing station I used was also the base for Severn Valley Motorsports (Ford specialists) with aeons of tuning experience, so 5 minutes later it passed s:wink: :wink: s:wink:
Quote from: "Slacey"(he did give the technical jargon name of the figure but I can't remember, but this equates to stoich)
Stoichiometric?
Quoteany reading OVER meant it was running lean and any figure UNDER 1 was running rich
Yeah, you can convert these to AFR, if you're more familiar with these s;) ;) s;)
AFR=14.7*LAMBDA
Quote from: "Slacey"I had my MOT last night and I asked the guy what exactly the Lambda test was. He stated that the perfect reading was 1 (he did give the technical jargon name of the figure but I can't remember, but this equates to stoich) and that any reading OVER meant it was running lean and any figure UNDER 1 was running rich. This surprised me somewhat as I'd always figured that I would run rich, but it seems that both times I have had a test that as I was around 1.3 I am running lean.
Anyway, I didn't realise until I got there but the testing station I used was also the base for Severn Valley Motorsports (Ford specialists) with aeons of tuning experience, so 5 minutes later it passed s:wink: :wink: s:wink:
come on then more info, what did they do to get it to pass?
They jiggered the Emanage map to suit, then returned it to my original map.
Quote from: "Slacey"They jiggered the Emanage map to suit, then returned it to my original map.
I have a feeling Mark was after what they did to your eManage map, Sean s;) ;) s;) s:D :D s:D
I guess perhaps add some injector duty (if it was lean) and perhaps adjust the timing a little for a more complete burn (to lower the CO figure back down again) - probably advance the timing a little, at a guess.
Sound right?
[edit] Oops, got advance & retard backward s:oops: :oops: s:oops: [/edit]
Your right, i've just checked my MOT failure sheet and it was
co 7.85%
hc 401ppm
lambda .791
Which was definatly rich so i had to take fuel out. Everyone else seems to be the other way around so they must of increased the duty to compensate.
Quote from: "aaronjb"I guess perhaps add some injector duty (if it was lean) and perhaps adjust the timing a little for a more complete burn (to lower the CO figure back down again) - probably advance the timing a little, at a guess.
Sound right?
[edit] Oops, got advance & retard backward s:oops: :oops: s:oops: [/edit]
Hmmmm, I'm gonna have to work on this one. My Lambda is a still a smidge lean but if I bring it down the CO fails. Perhaps I need to get this ignition harness assembled? s:shock: :shock: s:shock: Yo 'kin Ho s:lol: :lol: s:lol:
Any of you guys superstitious? Friday 13th was MOT day and my '2 is now officially very much off the road with a flunked MOT s:( :( s:(
I've dumped the old and tired NB sensors and have got the WB triggering the ECU - figured it would be more stable....... but it hasn't settled down yet.
Lambda is still too high (1.08 - 1.10) and CO is miles out. A quick blast round the block and CO briefly came down into pass territory but the MOT probe still gave a failed (lean) lambda, and never were the two passing at the same time s:? :? s:?
Looks like my next post will be under Private Sales. Oh well, FI was fun while it lasted. I am sooo hacked off s:cry: :cry: s:cry:
Bump
Whats the answer to this? im not confident to go turbo until I know I can get an MOT.
Also I must only be a few months from needing my MOT doing so its not like some people who have a year to sort it.
Philly
get your mot early then you have a year torectify any issues
can you realy get it a few months early ?
I believe you can get it at any time, and if you do it early and present your old MOT cert, you can get a 'long' MOT certificate (runs for 13 months, not 12)
Quote from: "philster_d"can you realy get it a few months early ?
Looks like it. My local garage offered a test before Christmas and a certificate to continue from the date of expiry (13th Jan).
If there is a time limit for overlap - and i suppose there must be - it wouldn't prevent you from getting 12 months on a new certificate and writing off what's left on your old one.
Unfortunately, I just ran out of time with duff emissions numbers. s:cry: :cry: s:cry:
*edit* He's quick that Aaron bloke s:wink: :wink: s:wink: */edit*