Hi,

 

As stated, my car failed it's MOT on excessive CO. I am using #6 rating NGK iridium plugs and running 10psi boost.

 

My results according to the tester were 4500 and they are supposed to be 3900 or less.

 

I have read a trick yo disconnect one of the vacuum pipes on the plenum, does this work?

 

Are there any other tricks I can do before I end up crawling into a corner and crying?

 

Does Redex do anything?

 

Any help is much appreciated.

 

Thank-you

 

Chris

 

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Your car is running correctly?

No boost leaks

Correct timing

Correct tps and base idle settings

The car was tested as a z32 not a 350z or something silly.

The car is running correctly yeah.

 

The tester could not find the car on the database. So he put it in as 'other' therefore only doing the HC and CO test.

 

How can I check the TPS and idle settings?

 

 

 

 

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What year is your Z?

I thought they were no longer on the system for emissions...

Never had mine done as "other"...... I thought they couldn't do emissions on cars not on the system??

What year is your Z?

I thought they were no longer on the system for emissions...

Never had mine done as "other"...... I thought they couldn't do emissions on cars not on the system??

 

Lex posted this on another thread a while ago.....

 

 

 

And here's the Nissans listed in the Annex.

 

 

 

- - - Updated - - -

 

Apologies for poor pic quality. Photobucket seems to have reduced quality.

I'll re upload from my laptop later tonight.

What year is your Z?

I thought they were no longer on the system for emissions...

Never had mine done as "other"...... I thought they couldn't do emissions on cars not on the system??

 

I'm struggling to read them pics.

 

I don't really know the rules to be honest, but it failed.

 

My Z is a 1993 Jap import TT

I'm pretty sure they cannot fail your car for emissions......... As a 300zx isn't on the Annex they cannot test for emissions if they have No reference, so it would go under this section... and that states it is only an idle test if I am reading it right...

emissions.pdf

 

Where are the MOT testers on here when we need them????

Edited August 9, 20168 yr by veilside01702

Has to be tested non cat test...should pass it easy...go back ask if tested non cat test and ask for print out...

Ask them to test it again post results up...

Should get emissions print out.

Probably tested wrong and he should do it non cat test and then pass car.

I'm an mot tester and other tester at work failed a car few weeks back it was not on system tested it with a cat...

Edited August 9, 20168 yr by Terry

Has to be tested non cat test...should pass it easy...go back ask if tested non cat test and ask for print out...

Ask them to test it again post results up...

Should get emissions print out.

Probably tested wrong and he should do it non cat test and then pass car.

I'm an mot tester and other tester at work failed a car few weeks back it was not on system tested it with a cat...

He did it as a non cat test yeah. The hydro carbons were fine. It's the carbon Monoxide that was high at 4.9, he said it's supposed to be 3.5.

 

Im going back on Thursday anyway but I need to do something to the car in order to make it pass

 

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Get it on a conzult and check everything is behaving.

 

Assuming it has been tested correctly, fully up to operating temperature, it could be a number of things. TPS, air leak, base timing (all as previously mentioned) as well as a potentially failing O2 sensor, incorrect fuel pressure, lazy injector or anything else that can make it run rich

I've a 91 tt and its never been tested on emissions in the 6 years since I got it ,they don't even stick anything in the exhaust I thought if it was after 96 you had to have cats and needs testing

I've a 91 tt and its never been tested on emissions in the 6 years since I got it ,they don't even stick anything in the exhaust I thought if it was after 96 you had to have cats and needs testing

 

It should have a BET (Basic Emissions Test) at the very least. I want to take my car to your test centre! :thumbup1:

If all else fails, this might work for you...

 

http://www.300zx-twinturbo.com/tech/co/co.html

If all else fails, this might work for you...

 

http://www.300zx-twinturbo.com/tech/co/co.html

Yeah I have read that thankyou. This is what I'm going to try when I take it for its re test.

 

If that passes the test I will then give the car a full tune up.

 

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It should have a BET (Basic Emissions Test) at the very least. I want to take my car to your test centre! :thumbup1:

 

Was the same when I had my Camaro z28 ,maybe there dodgy :innocent:

Disconnect the 02 sensors

I'm pretty sure they cannot fail your car for emissions......... As a 300zx isn't on the Annex they cannot test for emissions if they have No reference, so it would go under this section... and that states it is only an idle test if I am reading it right...

[ATTACH]100185[/ATTACH]

 

Where are the MOT testers on here when we need them????

 

Since you quoted me, I just wanted to clarify what I was referring to in the post you quoted.

 

the 300zx must still HAVE an emissions test. But it only has to have the BET (basic emissions test) which is conducted at idle.

The OP's car has failed as his CO emissions are too high. The BET max level for CO is 3.5%.

 

Most zeds would pass this easily (mine passed it comfortably when it had de-cats fitted).

 

I'm going to sound a little harsh here - but please ensure you know what you are talking about before passing on information. It could have been very embarrassing for the OP if he had shown up at the MOT testers shouting what you had told him whilst all the time he was incorrect.

Again, sorry if that sounds harsh.

That's fine Lexx... OP had said it was tested as other, but hadn't said if it was done on idle or any other info. I quoted your response on another thread as it seemed relevant at the time of posting. I just posted the MOT annex details so the OP could read the information a tester would use as a reference. I had no intention of confusing or wrongly directing the OP. That is why I asked for an MOT testers input....

I won't quote you again.

It finally passed, after a while of fettling.

 

Just an advisory on brake pipes and some idiot jacked the car up on the sills, bending the seams.

What was wrong with the car in the end?

What was wrong with the car in the end?

 

Ended up following this what AndrewG suggested

 

http://www.300zx-twinturbo.com/tech/co/co.html

Your going to fix the problem that causing it though right? Because that's obviously a bodge. Even fully decatted a Z32 should pass UK smog unless something's broken. Mine always has...

Your going to fix the problem that causing it though right? Because that's obviously a bodge. Even fully decatted a Z32 should pass UK smog unless something's broken. Mine always has...

 

Yes of course. I'm going to give it a tune up and do all the standard checks.

Hi guys,

I was having this issue, getting my Z through the MOT emissions test.

My son is a mechanic & MOT tester (recently qualified) and even he didn't know the path through the test for our cars.

Mine is a 1993 import. Because its an import then they have no data to test it against.

When the emissions test fail if they follow the instructions correctly they should then do a NON-CAT test which it passes easily.

I know someone else with a 300 who has his own garage and he said exactly the same thing.

You can see the charts that direct the MOT'er as oto how to test our cars on the VOSA site and that's what I showed my son.

He spoke with a very experienced MOT'er and garage owner and he agreed with what I found on the VOSA site.

If you cant find it and still having problems just let me know and I'll dig out the exact sheets/links for you.

Also mine was running normal unleaded and low spec plugs so I've just found out and it still passed.

Rex