What could this .3% be people?
I had a suspicion during the test that the tester was over-revving it so was annoyed to see the engine speed reading missing. Is that allowed?
It's my first MOT so not sure.
The readout suggests over-fuelling which would align with poor-ish fuel consumption. But I'm wondering where to start to be honest.
Please help!
MR2 emissions failure
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Many subjects will have been discussed before. Please try the search function before starting a new thread.
Check in the Know Your 2 as the information you need may already be there.
Important ! - Please make your topic title as descriptive as possible . titles with just "help" generally dont get as many answers as a title that points to the problem
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romford.dan
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Re: MR2 emissions failure
He was probably trying to improve the reading to get it passedromford.dan wrote: I had a suspicion during the test that the tester was over-revving it so was annoyed to see the engine speed reading missing. Is that allowed?
Method of Inspection
All vehicles
1. Raise the engine speed to around 2500 rpm or half the maximum engine speed if this is lower.
Hold this speed steady for 20 seconds to ensure that the inlet and exhaust system is properly purged.
Allow the engine to return to idle and the emissions to stabilise.
a. assess the engine idle speed.
b. assess the smoke emitted from the tailpipe at idle,
c. rapidly increase the engine speed to around 2500rpm or half maximum engine speed if this is lower and assess the smoke emitted from the tailpipe.
Allow the engine to return to idle.
Black is not a colour ! .... Its the absence of colour
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fingers99
Re: MR2 emissions failure
Yes.
A kind MOT man will try and get the cat well up to temperature before doing the tests. It gives the car a much better chance of passing.
A kind MOT man will try and get the cat well up to temperature before doing the tests. It gives the car a much better chance of passing.
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romford.dan
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Re: MR2 emissions failure
So over-revving would actually help? 
Well, if that's the case apologies to the tester.
Any help is appreciated. Could this just be the o2 sensor?
Well, if that's the case apologies to the tester.
Any help is appreciated. Could this just be the o2 sensor?
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_Al_
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Re: MR2 emissions failure
What spec / age is your car?
Red 92 turbo tintop JDM
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romford.dan
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Re: MR2 emissions failure
That would help wouldn't it?
It's a 1995 UK N/A. Recently serviced (except for dissy and leads) only modification is a K&N induction cone filter.
It's a 1995 UK N/A. Recently serviced (except for dissy and leads) only modification is a K&N induction cone filter.
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_Al_
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Re: MR2 emissions failure
Do you drive it often? If I was you I'd take it for a hard, high revving run in the countryside to clean out the cat then try again.
Red 92 turbo tintop JDM
White 95 turbo tintop JDM (Nov '11 Show&Shine Winner)
Red 97 NA tintop JDM
Blue 95 tubby tintop JDM
Mica 96 NA T-bar UK
Red 96 UK NA
Red 97 NA tintop JDM
White 95 turbo tintop JDM (Nov '11 Show&Shine Winner)
Red 97 NA tintop JDM
Blue 95 tubby tintop JDM
Mica 96 NA T-bar UK
Red 96 UK NA
Red 97 NA tintop JDM
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luke m
Re: MR2 emissions failure
It's only failed on the cat 0.19% which is a small amount, it would be worth while driving the car hard and getting the cat red hot, usually I stick any cat in second and. Third, flooring it then letting off then up again etc.
Once done get the emissions tested.
Worked wonders for the misses fiesta which was reading 1.703!!! Passed straight after.
And no, won't be the lambda.
Once done get the emissions tested.
Worked wonders for the misses fiesta which was reading 1.703!!! Passed straight after.
And no, won't be the lambda.
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romford.dan
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Re: MR2 emissions failure
I drive it 2-3 times a week normally one journey is over 30 miles. The day of the test i absolutely thrashed it around the B186 but looking back, i did not go as hard as i could have really. Will try the above and see how i get on. She's back in on Monday.
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luke m
Re: MR2 emissions failure
Was also holding it at 5000rpm for long periods in second at 40. Keeps things hot? This is the key.
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Chris_D
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Re: MR2 emissions failure
High CO indicates a rich mixture, but the lambda is correct.
I would suspect a slight exhaust blow between engine and O2 sensor, most likely between manifold & head. This allows air to leak in and gives a false weak reading which the ECU then compensates by adding fuel.
I would suspect a slight exhaust blow between engine and O2 sensor, most likely between manifold & head. This allows air to leak in and gives a false weak reading which the ECU then compensates by adding fuel.
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Chris_D
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Re: MR2 emissions failure
luke m wrote:Exhaust leaks cause high lambda readings not high co
If the leak is after the O2 sensor then yes - the reading indicates weaker than the actual combustion.
If the leak is before the O2 sensor then the ECU will compensate for the 'weak reading' and add extra fuel bringing the lambda reading back to correct but with actual combustion rich (as indicated by the CO).
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G4gav
Re: MR2 emissions failure
is it a import?
if so this might be of help to you ,
The vehicle will be tested according to its age from first use-The only exemption to this is if the vehicle owner can present to the tester at time of test a letter from the vehicle manufacturer stating that the particular engine as originally installed could not meet the equivalent British emission standards. If this is the case, then test to the next lower emission standard.
e.g. A 1995 car first used in Africa has a letter from the engine manufacturer stating that the particular engine (engine number to be stated) cannot meet Catalyst emission limits, then use the pre cat limits of CO 3.5%, HC )200ppm.
just mine was just over too at one mot station and took it to a another and then he told me this info and then it passed with not excessive ranting before going in.
if so this might be of help to you ,
The vehicle will be tested according to its age from first use-The only exemption to this is if the vehicle owner can present to the tester at time of test a letter from the vehicle manufacturer stating that the particular engine as originally installed could not meet the equivalent British emission standards. If this is the case, then test to the next lower emission standard.
e.g. A 1995 car first used in Africa has a letter from the engine manufacturer stating that the particular engine (engine number to be stated) cannot meet Catalyst emission limits, then use the pre cat limits of CO 3.5%, HC )200ppm.
just mine was just over too at one mot station and took it to a another and then he told me this info and then it passed with not excessive ranting before going in.
