MoT FAIL!

[mutley]

Hi all,

Had the car in for an Mot today, and it failed on emissions. I found this a little strange as even with the De-cat exhaust. I have had this exhaust on the car for about 5 yrs now and it has always passed the test. Any ideas why it would be suddenly be a fail?

My only reasoning behind it, is that since the last MoT, the car hasn't really done many miles and even today I just took it straight to the Honda garage without a decent run (didn't want to risk going to far with the car as without MoT it's not technically road legal).

Anyone any tips?

Cheers
Jim

[L696ULO]

A few years ago when the garage tested my car's emissions it didn't pass and that was after a 15 mile drive to get there. I hadn't used the car that much beforehand however they held the revs at 3,000 for about a minute and it then easily passed.

[Kaz-kzukNA1]

Hi, Jim.
What was the CO, HC readings? Surprised you managed to exceed 3.5% and 1200ppm....
How old is your fuel inside the tank?

You are allowed to drive the car without MOT if you can prove that you have an appointment for the MOT and you are on the way to the MOT station.

Kaz

[mutley]

I do usually take it a decent run before hand.

Kaz, there was some old fuel in the car, but not a lot, and I did put in about 30 litres of fresh fuel. There were another few fail points (corroded rear brake line and a number plate bulb) but I was just surprised at the emissions as I've never had any problems with that before.

I'll post up the emission results later (I'm out on my phone just now)

Cheers
Jim

[mutley]

here are the emission results:

Fast Idle Test : CO limit <=0.3% Result : 0.67% FAIL
HC limit <=200PPM Result 152 PPM PASS
Lambda 0.97 - 1.03 Result 1.04 FAIL

Second Fast Idle Test: CO Result : 0.71% FAIL
HC Result 187 PPM PASS
Lambda Result 1.03 FAIL (but surely thats on the limit!)

Natural Idle Test: 650-950 RPM
<= 0.5% Result 0.47% PASS

[Kaz-kzukNA1]

Hi, Jim.

That result is based on the BET criteria.
Is your NSX first used before or after 01/Aug/92?

This will decide whether your NSX needs to go through the ‘non CAT test’ or the ‘BET (Basic Emissions Test)’ followed by another procedure if it didn’t pass the BET first.

Probably all of your previous MOTs were done using the non CAT test because your NSX is used before 01/Aug/92 or even if it was not the case and it failed the 1st BET, the operator used the criteria of 'couldn’t find the exact match in the analysis database….' and thus, carried out non CAT test as specified by the VOSA.

So, the key is to find out whether your NSX was used before 01/Aug/92 or not.

Kaz

[mutley]

Kaz,

I think the database shows my car at first registered 01 Aug 92 .

When I get back down south next week, I'll check last years MoT to compare results
Jim

[mutley]

HI All,

Watch this space, tomorrow I am going back to the Honda dealer that tested my car. I found last years MoT ( Same dealer) and the car passed no problems. on examining the 2 MoT certificates, at first I could;t see the difference , then i noticed the heading on the top. Last year they the test was un-catalytic converter, this year (the fail one) was a test with Cat - that will explain the fail as my car does't have cats fitted, so I will be presenting them with this tomorrow and see what they say.

Cheers
Jim

[Dragonlady]

Good luck, keep up posted.

[Hagasan]

HI All,

Watch this space, tomorrow I am going back to the Honda dealer that tested my car. I found last years MoT ( Same dealer) and the car passed no problems. on examining the 2 MoT certificates, at first I could;t see the difference , then i noticed the heading on the top. Last year they the test was un-catalytic converter, this year (the fail one) was a test with Cat - that will explain the fail as my car does't have cats fitted, so I will be presenting them with this tomorrow and see what they say.

Cheers
Jim

Hi Jim,

normally pre-93 cars (usually pre-K Reg) such as yours do not have to do the stricter MOT test even if the cat is fitted. I had this in the past when I previously owned my Porsche 944 Turbo and 964RS. Porsche were an early adopter of fitting cats universally to their cars (probably due to stricter US emissions rules in California etc, a big market) before the requirement in other parts of the world. It should only be 93 onwards cars that do the full emissions tests?

Incidentally, going to the garage tomorrow? Are they open on Good Friday for MOT's??

Cheers,

Gary

[Kaz-kzukNA1]

Hi, Jim.

As your NSX is first used on or after 01/Aug/92, you will need to follow the BET first and not the non-CAT test.

However, simply failing BET won’t become straight MOT failure.
The operator will then need to either find the 'vehicle specific limit' for the CAT test or if not available, carry out the non-CAT test.
I think your previous MOTs were carried out based on the latter condition.

Good luck with the test.

Kaz

[NSX100]

A few years ago when the garage tested my car's emissions it didn't pass and that was after a 15 mile drive to get there. I hadn't used the car that much beforehand however they held the revs at 3,000 for about a minute and it then easily passed.


The same happened with me last year. The car initially failed on emissions but they ran the engine for about 30 minutes, re-tested it and it passed, just. Like many others, the car had been essentially stored over the winter and driven very little beforehand. The garage warned me that it needs a long run before being tested.

[mutley]

Hi all ,

At Honda now, and even though they passed my car on the no cat test last year, they are refusing to give it the non cat test this year stating as it was registered 91 Aug 1992 they say it has to be the Cat MoT test. I asked why they passed it on the non cat test last year and got blank looks

[Pride]

What a bummer!!! Sounds like typical motor trade though.:(

I presume you've changed your oem exhaust which is why you no longer have any cats, if so could you not just refit the origanol for a retest, I know it's a real pain but at least it would get you out of this hole???

[mutley]

What a bummer!!! Sounds like typical motor trade though.:(

I presume you've changed your oem exhaust which is why you no longer have any cats, if so could you not just refit the origanol for a retest, I know it's a real pain but at least it would get you out of this hole???

Yes I still have the original exhaust, it's jus annoying that the passed it previously but are refusing now. I could re fit old exhaust for the test, but I'll probably just go elsewhere !!
Cheers
Jim

[mutley]

Hi, Jim.

As your NSX is first used on or after 01/Aug/92, you will need to follow the BET first and not the non-CAT test.

However, simply failing BET won’t become straight MOT failure.
The operator will then need to either find the 'vehicle specific limit' for the CAT test or if not available, carry out the non-CAT test.
I think your previous MOTs were carried out based on the latter condition.

Good luck with the test.

Kaz

Hi Kaz,

That's exactly what I explained to them today, but it seems that they are now unwilling to do that (even thought hey passed it last year that way).

I think I'll just go elsewhere.
Cheers
Jim

[Pride]

Yes I still have the original exhaust, it's jus annoying that the passed it previously but are refusing now. I could re fit old exhaust for the test, but I'll probably just go elsewhere !!
Cheers
Jim

Careful with going else where Jim as the emission results and failures are now on record thanks to an EU ruling in 2013.
What I would do is ask a friendly garage which do MOT's and just ask for an emissions test stating its pre-cat, some would do that for nothing and if the emissions are all good then explain to the proprietor your scenario with the other test station and I'm sure he would help you with doing another MOT.

Good luck anyway.

[mutley]

Pride,

That's pretty much what I have planned, I have another garage that I use for all the work on my RRS (and he's ex RAF, and we were both based at the same unit, so that helps).

There were a couple of other items that failed(corroded brake line) but I won't be off the road for too long

Cheers
Jim

[soddy]

I brought my rx8 for testing and as I had gone up early to let the engine cool down, as they switch them on and off like a yoyo for brakes etc.
I got called in earlier than my time and was creeping over to the center to let the engine and CAT warm up a little more, but they told me to rev
to 2k and I just made it through.

Some testers can be funny but I passed the test regardless. Thing is alot of the rx8's have little brick left and still pass and with a rotary
engine they run very hot and be in the higher emissions band. A good blast should help but if you have a friend who can help you out all the better,
if not then get the old exhaust on to get her through the test.

[mutley]

Hi all, unfortunately I don't have time to do anything so the cover is back on the car.
If I have to put the oem exhaust on for the test then so be it, but I am more perplexed that this is the first time that have refused it (passed with this exhaust on the last 5years) and the fact the Honda dealer passed it last year. A bit of consistency would be good, either I need cats or I don't .

Cheers
Jim

[Kaz-kzukNA1]

Hi, Jim.
The regulation and the manual are consistent but not the operators, I’m afraid….

You can download the MOT manual from the government site.
https://www.gov.uk/government/publications/mot-inspection-manual-for-class-3-4-5-and-7-vehicles

For your NSX, it’s section 7.3 page 6, 7 and 9 are the key.

Honda garage was correct in stating that your NSX must take BET because your NSX was used on or after 01/Aug/92.

However, failing BET doesn’t become the reason for MOT fail and it’s clearly written in the manual as well.
Once it didn’t pass the BET, then the operator would follow the question shown on the display so not sure why they didn’t follow it or possibly followed it, found the exact match in the database for the specific emission limit for your NSX and then failed it on that basis.

I went through the MOT procedure and the actual description shown on the display at my local Honda garage as my NSX is JDM and I imported it by myself so they required extra support from me.
If you don’t follow the correct flow, you would end up with the wrong criteria. 1st time when they went through, they made the mistake.

One can reject the certificate if the CAT was removed from the vehicle that was fitted as standard but it’s only for the vehicle qualifies for the Full CAT emission test and since your NSX doesn’t belong to that group, removing the CAT doesn’t become the reason for MOT fail.

Hope your friend can help you.

Kaz

[mutley]

Thanks Kaz, However it looks like it will have to wait for a few months, I am deploying overseas again ( Estonia this time) until September, so with a bit of luck I can get the car back on the road then.

Cheers
Jim

[simonprelude]

Send me the keys Jim, I'll sort it ;)

[mutley]

Send me the keys Jim, I'll sort it ;)

If only it was that easy Simon !! cheers anyway though

Jim

[mutley]

Hi All,

Well I have had a crazy few years, (plenty travel but all work related !!)

Anyway, My car is FINALLY in for MoT, having been SORN'd for sooooo long, I am itching to get it back legal and running again.

I have found someone local to me to do little bits of work to the car, but still yet to see how "sympathetic" the MoT garage will be.

As some of you know, I have had the odd little issue with my car, but we will see if it gets through this year! IF it does, then watch this space :)



Cheers
Jim

[mutley]

............. and here is the latest. yea the poor old car failed again, but on all fairly minor issues bar 1. Even though my car is a 1991, because it was registered 1 August 1992, it requires a Cat. Although slightly annoying, rather than playing around refitting old exhaust for MoT, I’m getting 2 Sport Cats fitted into the exhaust system.

I’m not giving up, it WILL be road legal again.

Cheers
Jim

[Graham]

Mine is a '91 with sports cats, registered as a '93 and is always tested as a '93. It's a worry every year.

My procedure is put some decent fuel in it and blast it down the M5 and back for 20 miles immediately before the MOT .

My instruction to the MOT tester is if it fails on emissions, take it up the road and rag the balls off it, just don't red line it, and test the emissions immediately afterwards.

Seems to work!

[goldnsx]

To pass emissions the best way a professional of a laboratory for emissions testing told me years ago to rev it on the highway to constantly 5-7k rpm for an extended period of time (20-30 minutes?). This heats up and cleans the cats. No need to drive like you stole it. WOT at AFR 13 won't be ideal for the cats to clean.

Another once told me that longer storage time could harm the cats efficiency. He recommended me to drive it more frequently (daily) before MOT.

[Senninha]

Sports CATs plus a good run on optimax (or similar high octane) and hopefully you have her back on the road before the first snow falls

[mutley]

Hi all, that is the plan, I'll see what happens one the Cat's get fitted, but I think it's all positive (also needed track rod end which are coming from Japan, I told the garage to do both sides, if 1 is going the other wont be far away).

Everything is going in the right direction, so fingers crossed. I'll updated when I hear back from them.

Cheers
Jim

[mutley]

Hi all,

Quick update:

So with the additions of 2 x Sport Cats fitted, new track rod ends, a few minor headlamp tweeks, I now have a road legal NSX again.

I'M BACK.

Cheers

Jim

[goldnsx]

Glad to hear.

[NSXGB]

Well don Jim, now start fitting all those parts you've been stockpiling!

[mutley]

Well don Jim, now start fitting all those parts you've been stockpiling!

Hahah and I know you are not kidding!! I’ve got plenty to be getting on with!

Cheers
Jim