My car has just failed it's MOT, apparently on fast idle emissions.
Technician has had a look and reckons it's because the precats aren't there and bank 1 o2 sensor is reading too high.
On a side note they told me that it's quite common for the precats to die, but there's usually some there so they wondering whether they were removed...
No it's not the unichip as that's not on there.
Any ideas on what could be wrong, bar doing a general ECU reset and clean the MAF etc?
was your car warm when they did the emissions check?
you need teh prercats to pass from cold, but if it's hot you should be fine
Good point, i can't imagine they'll have warmed it up first, especially if it's meant to pass when it's cold.
I will double check with them.
Crud, my car is getting its MOT this saturday (sans precats) - is it common that they fail the emissions test s:shock: :shock: s:shock: - now im a bit worried....
make sure you turn up in teh car for teh time booked so it's still warm rather than leaving it wait all day until they are ready
Cars in the UK do NOT require pre-cats, and hence should only be tested once the vehicle is warm.
There is a prescribed minimum run time prior to the test being performed, and this should be plenty of time for our main cat to reach operating temp given the short exhaust length compared to most front engined cars.
The pre-cats are a requirement to pass Californian emissions laws
ok, thanks for that, i'll give her a good beasting on the way to the test center s:twisted: :twisted: s:twisted:
Stats:
Fast Idle test:
CO: 0.48% Vol - fail, (<= .30% pass)
HC: 17ppm vol (<= 200ppm pass)
Lambda .990 (pass range: 0970-1.030)
Second fast idle test
CO: 0.47%
HC: 7ppm
Lambda: .990
Diagnosis, no precats (obviously), faulty O2 sensor?
I had no CEL so i don't know whether they've borked the O2 taking a look at precats or what...
they say the car was warm as the machine won't let them procede if it isn't at the right temp.
Quote from: "Bongo"Stats:
Fast Idle test:
CO: 0.48% Vol - fail, (<= .30% pass)
HC: 17ppm vol (<= 200ppm pass)
Lambda .990 (pass range: 0970-1.030)
Second fast idle test
CO: 0.47%
HC: 7ppm
Lambda: .990
Diagnosis, no precats (obviously), faulty O2 sensor?
I had no CEL so i don't know whether they've borked the O2 taking a look at precats or what...
they say the car was warm as the machine won't let them procede if it isn't at the right temp.
Perhaps it is your main cat that is the problem then?
2 courses of action here for you...
1, is to change the air filter, clean the MAF, and run a bottle of injector cleaner through the tank. Then thrash it like a ginger stepchild all the way to the MOT station, and put it straight on the machine.
2, is to find a more leniant MOT tester, that CO readings not that bad, so option 1 would in liklihood be fine.
Quotethrash it like a ginger stepchild
s:lol: :lol: s:lol: s:lol: :lol: s:lol: s:lol: :lol: s:lol:
Mines just passed the emmissions test without pre-cats (engine was warm) - failed on the non-existant handbrake tho s:oops: :oops: s:oops: DOH
Quote from: "slayer"failed on the non-existant handbrake though
What's one of them ?
Quote from: "GSB"1, is to change the air filter, clean the MAF, and run a bottle of injector cleaner through the tank. Then thrash it like a ginger stepchild all the way to the MOT station, and put it straight on the machine.
This is what I would have gone for. Considering as we know the 2 can pass an MOT without the pre-cats, we know we can rule that out as being the problem.
Try going for the above and then the old unplug the battery for a while to reset the ECU.
A couple more questions:
1) Have you any engine mods, no matter how small?
2) Where fuel do you use (Optimax, Ultima, Tesco 99RON etc)?
I ask because it might help narrow down MOT failures in the future and lead to a more instant diagnosis for any future problems.
Quote from: "GSB"2, is to find a more leniant MOT tester, that CO readings not that bad, so option 1 would in liklihood be fine.
But with the new computer based MOT tests wouldn't that make this impossible now?
Quote from: "Peter Laborne"2) Where fuel do you use
I could have just edited that bit....but:
ALL YOUR BASE ARE BELONG TO US s:lol: :lol: s:lol:
Quote from: "GSB"2 courses of action here for you...
1, is to change the air filter, clean the MAF, and run a bottle of injector cleaner through the tank. Then thrash it like a ginger stepchild all the way to the MOT station, and put it straight on the machine.
2, is to find a more leniant MOT tester, that CO readings not that bad, so option 1 would in liklihood be fine.
I was planning on a bit of both...
Quote from: "Peter Laborne"A couple more questions:
1) Have you any engine mods, no matter how small?
2) Where fuel do you use (Optimax, Ultima, Tesco 99RON etc)?
1) Markiii pipe (also noticed by the dealer...), TRD filter, H&S exhaust.
2) I usually fill up at shell mostly on regular with the occasional optimax.
A further look at the paperwork reveals the test was carried out at 11am, so the car had been sat around for 2 hours. Oil temp was 60 degrees C which is the minimum allowed for the test.
I believe the TRD filter is cleanable and reusable? How would I do this?
MAF and ecu reset is easy enough, will a nice thrash to the test centre be enough for it to have "learnt", will a longer drive be necessary or will it be ok even if freshly reset?
Lambda sensors become weaker/slower over time. Try swapping the Lamda sensors over to see if the high reading moves with the sensor, if it does you know what the problem is.
Alternatively, borrow some sensors off someone elses car for the test and see if that works.
My old Scorpio went in 8 times before she passed
check for exhaust leaks
Liz's failed due to a leaky joint between her cat and H&S apparently it sucks in air and screws up the readings
If you have a free retest just go for a long drive then drop in for it "while you wait" it will surely be red hot then.
Cat converts CO to CO2, so I bet it's the cat. If the car was at normal temp, it would mean a dying cat, but if it was cold, it just means the cat wasn't operating yet.
Quote from: "stevewarbs"Lambda sensors become weaker/slower over time.
I don't think that's it, cause his lambda values are just fine.
Quote from: "markiii"check for exhaust leaks
That should show as high O2 reading, not CO.
I'm with the most, just retake the test when it's warm. s8) 8) s8)
Thanks for all the advice so far...
I'll post any updates here.
The natural Idle result was fine - a pass!
Quote from: "Peter Laborne"Quote from: "GSB"But with the new computer based MOT tests wouldn't that make this impossible now?
Apparently there are still places where as long as the car turns up you can gaurantee a pass.
I also believe you have to rebook for a retest now and they carry out a full MOT not just the fail parts.
Quote from: "Bowman"Quote from: "Peter Laborne"Quote from: "GSB"But with the new computer based MOT tests wouldn't that make this impossible now?
Apparently there are still places where as long as the car turns up you can gaurantee a pass.
I also believe you have to rebook for a retest now and they carry out a full MOT not just the fail parts.
I went to my MOT station today - once I had sorted out the dodgy handbrake !! The chap checked the handbrake which was fine and then booked me in for a
full retest on Monday at £22. He told me that the rules are changing soon and cars will be retested on only those parts that failed the original test and anything associated with that part of the fail. So things should get easier. s:wink: :wink: s:wink:
Mine past yesterday with flying colours (with out the pre cats) £45 tho, ooft s:( :( s:(
Hmm my tubby failed last year on 2 things and I only had to go back the next day to confirm they were done. Not a full retest.
Phil
Quote from: "Bowman"I also believe you have to rebook for a retest now and they carry out a full MOT not just the fail parts.
If your vehicle leaves the test center then you have to rebook a complete retest. If you leave it with them and fix the problem there then they can just test what failed.
I just logged on to the site with the intention of posting about this very subject. Just had our MR2 in on Friday for its second MOT, its first since removing the pre-cats almost a year ago. It passed with flying colours, and the emissions were actually slightly lower than for last year!
The car was warm as I'd just had a spirited drive there and they pulled it straight into the garage to commence the test.
Quote from: "Peter Laborne"Quote from: "Bowman"I also believe you have to rebook for a retest now and they carry out a full MOT not just the fail parts.
If your vehicle leaves the test center then you have to rebook a complete retest. If you leave it with them and fix the problem there then they can just test what failed.
Depends on the test centre, and what failed. Certianly its possible to get a free retest on certain items, but the time limits have changed.
See m http://www.motester.co.uk/retest.html (http://www.motester.co.uk/retest.html) m
.. that shows a retest on emissions can be done for free providing it is the next day. Doesn't leave you much leeway to order parts in and fix it yourself though.
FWIW - my Roadster turbo passed its MOT earlier this year - I put the standard Main Cat and Back box back on the car. No Precats thanks to the PE turbo.
High CO = incomplete combusion usually, and should be cleaned up by the cat - but you could have some tired spark plugs, so I'd try fitting some new NGK plugs.
If that doesn't work, you probably need a new cat s:( :( s:(
Found out something interesting today as mine was having it's MOT. I have the TTE twin exhaust and I saw one of the other grease monkeys crowched down next to one of the popes blocking it off. When I asked why he was doing that I was told that it would definately fail on emmissions if it wasn't blocked off for the test.
Apparently a lot of test centres know this (it's the same for nearly all multiple exit and/or large tailpipes) and will deliberately not cover up one pipes knowing they can fail you and you will have to bring it back. They will then misdiagnose possible problems safe in the knowledge that this will mean they can get labour rates out of you as they pretend to try and fix it.
Quote from: "Phil-yarde"Quotethrash it like a ginger stepchild
s:lol: :lol: s:lol: s:lol: :lol: s:lol: s:lol: :lol: s:lol:
Oh, that is so NOT funny it's untrue! s:shock: :shock: s:shock:
*rushes off to buy bottle of hair dye* s:lol: :lol: s:lol:
Why Peter ? because of the pipe layout and the reality that one can usualy act in reverse sucking in some air ?
They didnt cover up one of my pipes, and it passed the MOT fine - I watched them doing it. I cant see how covering up one pipe will alter CO2 emmissins - plase correct me if I am wrong. s:? :? s:?
Replaced an O2 sensor that had completely lost it's thread.
Passed the emissions fine afterwards, CO emissions down 100 fold s:? :? s:?
just failed my co test.
stats: oil temp 96'C
fast idle : CO 0.58%
HC 30ppm
Lambda 0.87
second fast idle : CO 0.91%
HC 34ppm
Lambda 0.97
natural idle : CO 0.15%
and failed on handbrake too (lol).
just spoke to a guy (not an mr2 specialist but a mechanic, he suggests that it it could be as a result of me swapping the stock filter for a K&N ??? He told me of an Alfa that had the same prob, and that when he went back to a stock filter it passed. He also asked if i had an induction kit, which i dont.
Does anyone know where in manchester (pref north around bury) where they will do a free emissions test. and secondly, does anyone have a stock air filter i can borrow for a few days please. I will collect or pay for postage (what ever is easiest)
i was absolutely gutted - infact i still am ! My baby is poorly. In fact it did smell fairly bad in the testing bay after a while, not pungent but defo something in the air. They are a bob on station and the dudes there look after you.
Just for reference its THE AIRPORT GARAGE on the A57 infront of Barton Airport. I always go there cos the guys are old boys, spot on and they DONT DO REPAIRS so they aint looking for extra income. Only down side is that you either have to drop it off, or wait with it.
Okies, thats my rant over, im off to bed now having started work at 7pm last night, just got home, and only got 4 hours sleep the previous night. Hardly the gentle slip back into work after my holiday !!!!.
The retest is now £20 if its done within 10 days or a full retest. The regulations changed last week.
E
Air filter would surprise me .... but.....
There may be a clean-ish stock filter in the airbox I gave to Nic (Wabbitkilla) last week - can't remember if I took it out but I probably didn't. Got an old one kicking about in the garage too.
i too wonder if a paper filter from mr2 could make much difference. still im more than happy to give it a go rather than start pokin about with o2 sensors and stuff that i am obliged to break !!!
i did an ECU reset and looked at the MAF about 2 months ago. DO you think its worth doing that again?
the posting about the ginger step brother thrashing - correct me as i am no scientist - would this not make the mixture richer = more power.
richer mixture = less complete combustion? just guessing and willing to try anything.
Nights is a right PITA, although should we get bad weather i will be able to use WEASELCHOPS' fantastic article on handbrake adjustments.
pencil me in for the old filter please Spit pending someone coming up with an alternative. Jolly decent of you, but then again i would have thought nothing less !
E
Quote from: "enid_b"Just for reference its THE AIRPORT GARAGE on the A57 infront of Barton Airport. I always go there cos the guys are old boys, spot on and they DONT DO REPAIRS so they aint looking for extra income.
Always take my cars to the local council garage. The place where they maintain all the buses, lawn mowers and trucks. Obviously they don't do any repair work on public cars so always very leniant.
My last two cars both had decat pipes and with a bit of jiggery pokery he's always scraped them through the emissions.
Everyone needs a pet one eyed MOT man. s:D :D s:D
Quote from: "enid_b"mechanic....suggests that it it could be as a result of me swapping the stock filter for a K&N
Had the same reason given to me upon failing a previous MOT with a K&N filter in - was told that oil from the filter could be fouling the MAF. Anyway, true or not, the car passed fine after cleaning the MAF. I know you said you did this a couple of months ago, but may be worth at least having a look ?
Ally.
I've got a TRD panel filter and had no difficulties passing at the second attempt, CO was well within the boundary. Might not have the same sort of oil though?
"Thrashing like a ginger step child" was to make sure the main cat was warmed up properly due to the lack of precats in my car.
TRD isn't an oiled filter
Quote from: "markiii"TRD isn't an oiled filter
Are you sure -
Quote from: "TRD"TRD High Performance Reusable Air Filters Pre-Oiled, washable and reusable.
There's also a cleaning kit, but TBH I haven't got round to even looking at it since it went in.
there were 2 types
I beleive the early one was oiled
so has anyone got a filter in manchester that i can borrow for a bit please. (not dissin urs spit, just holdin out for a {possibly} newer/cleaner one).
would swap for my k&n one obvioulsy so u would not be without?
found a scheme offering free emissions testing - a roadshow that travels round manchester. next few days in rochdale.
imagine how pleased was i...........until further reading showed it was in 2004
je suis un grand turnip
E
Quote from: "enid_b"(not dissin urs spit, just holdin out for a {possibly} newer/cleaner one).
NP matey.
The one in Nic's box isn't new, but it sailed through an MOT in Feb last year and came off the road in September. No idea what condition its in but its free if Nic doesn't have a use for it s:wink: :wink: s:wink:
Quote from: "markiii"there were 2 types
I beleive the early one was oiled
Yes that's correct. Mine was a later non oiled type s:wink: :wink: s:wink:
Apparently a lot of test centres know this (it's the same for nearly all multiple exit and/or large tailpipes) and will deliberately not cover up one pipes knowing they can fail you and you will have to bring it back. They will then misdiagnose possible problems safe in the knowledge that this will mean they can get labour rates out of you as they pretend to try and fix it.[/quote]
This is a load of shit .... I'm an mot tester and Ive never seen a car fail because I havnt blocked up the other pipe !! .... And the high co reading would be alot higher if there was no cats working . If yous all lived near newcastle yous could have a bullshit-free, mot. I dont fix cars so no need to fail them on ficticious problems !!! Ha Ha its so funny listening to crap some garages fill people with !!!!
Quote from: "enid_b"so has anyone got a filter in manchester that i can borrow for a bit please. (not dissin urs spit, just holdin out for a {possibly} newer/cleaner one).
would swap for my k&n one obvioulsy so u would not be without?
found a scheme offering free emissions testing - a roadshow that travels round manchester. next few days in rochdale.
imagine how pleased was i...........until further reading showed it was in 2004
je suis un grand turnip
E
I've got a pretty new one you can borrow if you like, I'm based just outside Leek in Staffs - let me know.
Thanks
Rob
thanks for the kind offers spit, and FGrob.
went and bought one, it was only a tenner from mr.t
sad thing is it looks like my cat is terminally ill. poss due to engine about to cark it.
what a fabulous day im having