Hello all

 

Mot is due in a month and I have a decat pipe - what's the situation with this as everything I read is rather confusing!!

 

1994 jap import turbo manual

 

Regards William

Also when I check mot history online emissions is N/A ?

Also when I check mot history online emissions is N/A ?

Me too. I think it's a new feature.

You can decat that without issue, it will still pass the required 3.5% test.

Also when I check mot history online emissions is N/A ?

 

That's because the Z32 is not listed on the emissions database.

That's because the Z32 is not listed on the emissions database.

 

Due to this, the 300zx should be put through a BET examination (Basic Emissions Test) with Co2 readings of 3.5% or less as mentioned earlier.

Also, if I understand correctly, this only needs to be done at idle also unless the hydrocarbon limit is exceeded.

word on the street is new laws came in this year regarding cats and dpfs,im told if a cat/dpf was once fitted and its been removed it should fail

Edited October 27, 20169 yr by jimmer

word on the street is new laws came in this year regarding cats and dpfs,im told if a cat/dpf was once fitted and its been removed it should fail

 

It's another rule which is almost impossible for us testers to enforce, who knows what car had a cat fitted previously?..... Any doubt as usual is given a pass and advise.

word on the street is new laws came in this year regarding cats and dpfs,im told if a cat/dpf was once fitted and its been removed it should fail

 

I've been told that for years now. But how can the tester prove that the 300ZX had cats from the factory. There are no databases to reflect that.

It is a tough one,dangling cat overheat sensor wires are quite a give away and loads of cars have this,or the aiv pipes still present appearing from behind the arch liner.Its a gamble these days.Exhausts are another problem,if its louder than another model with a standard system in good condition its supposed to fail also !

I'd just stand there on the bold as brass blag and inform them that "it's an import and they didn't come with cats till 93, only UK and Euro models were fitted with cats before this date. So being an 89 it's never had cats." Either they believe you or call you a liar (which you would be) but to hell with it.

Interestingly my MOT last year states "exhaust system noisey" in the advisory section. Does help I have removed the AIV etc.

Edited October 28, 20169 yr by Stephen

It is a tough one,dangling cat overheat sensor wires are quite a give away and loads of cars have this,or the aiv pipes still present appearing from behind the arch liner.Its a gamble these days.Exhausts are another problem,if its louder than another model with a standard system in good condition its supposed to fail also !

 

Dangling sensors or probes mean nothing to me as an mot tester, I cannot be sure or refer to any database to check for cat fitment as Joel stated, therefore I must pass it, as for exhaust being loud, we don't possess db meters so we cannot fail it for being loud unless for example it didn't have any exhaust from down pies back. Same thing with tinted front windows, they can be black as you like and I will happily pass your car on the mot, but mr plod will still give u a ticket.... Silly but that's how it is.

Do I legally need back boxes? Or can I run actual straight through? :devil:

Do I legally need back boxes? Or can I run actual straight through? :devil:

 

I would happily pass it mate, but the rozzers might hunt you down.....:laugh:

I take it it's not a testable fail then? Just not legal lol.

Not an outright fail because your particular car with its straight through exhaust pipe might not be "excessively" loud to me, therefore I can and will happily pass it, the key word is excessively, what one perceives as excessive will differ with another, an element of doubt has crept in and as usual we must always give the benefit of doubt to the vehicle presenter, pass and advise......

In all honesty the mot is pretty pointless, the majority of cars on the road now have that much underbelly plastic bolted to them you can't see sod all to test it properly, if you can't see it you can't test it, it really is just a waste of time...

The manual is quite clear and reads as follows - A silencer in such condition, or of such a type,

that the noise emitted from the vehicle is clearly

unreasonably above the level expected from a

similar vehicle with a standard silencer in

average condition

 

It may seem a grey area but if you read the wording its pretty clear to me to to pass something that sounds like a vulcan on take off is a no,If VOSA rock up to QC the car.Youd get points for passing it .No mention of excessive.I sat the course 8 years ago and Vosa dont like grey areas as far as testing is concerned.If in doubt pass and advise but if a vehicle is clearly way louder how would you argue that ?

to pass something that sounds like a vulcan on take off is a no

 

Haha [emoji23]

The manual is quite clear and reads as follows - A silencer in such condition, or of such a type,

that the noise emitted from the vehicle is clearly

unreasonably above the level expected from a

similar vehicle with a standard silencer in

average condition

 

 

 

It may seem a grey area but if you read the wording its pretty clear to me to to pass something that sounds like a vulcan on take off is a no,If VOSA rock up to QC the car.Youd get points for passing it .No mention of excessive.I sat the course 8 years ago and Vosa dont like grey areas as far as testing is concerned.If in doubt pass and advise but if a vehicle is clearly way louder how would you argue that ?

 

It also states that the method for inspection is to assess subjectively the effectiveness of the silencer at reducing noise, Stephen asked if missing back boxes was a fail, which it isn't, and as I said if his particular car with no back boxes was still not "excessively" loud then it would pass fine, and I also said that if no exhaust was fitted from say the down pipes back then that might well fail on it's level of noise.

 

Think of something like a TVR chimaera for example, how loud are they at 3000rpm? Can I fail it? No.

 

I may not know what a standard exhaust sounds like or looks like on a Z32 so I cannot be SURE if I'm hearing one during a test.

 

MANY grey areas exist on an mot......

You could even present your car to me with no bumpers fitted, providing your displaying your reg plates and any required lights are present I will give you a pass....