What setting should be used to test Import Emissions?

[Daston]

Hi guys,

Took my 1997 RX7 to an MOT today and it failed horribly on CO% during the emission test. The car is completely standard apart from a Cat back exhaust and the garage think my Cat is knackered. However with the way the rotary engine is I am not 100% sure they are testing it correctly.

We tried the first test as a UK RX7 which it failed big time. We then tried to test it on the basic Cat test and again it failed.

The HC and Lambda readings were also out but not by much and all readings were consistent.

I have gone through the paperwork and the previous years it has passed without issue.

Can someone confirm what they should be testing?

[blueedge]

The issue with the RX-7 is they tend to run a little rich on the fuel mixture which is going to cause the high CO readings. It's possible in previous years that a "friendly" MOT tester was used. Have you tried giving the car a really good hard drive to get the cat as hot as possible before testing?

[Daston]

blueedge said:

The issue with the RX-7 is they tend to run a little rich on the fuel mixture which is going to cause the high CO readings. It's possible in previous years that a "friendly" MOT tester was used. Have you tried giving the car a really good hard drive to get the cat as hot as possible before testing?

That may very well be the case, last MOT shows it had CO of 0.1% and now it's at 3.4% during the test.

Car had been sitting on idle for a little bit before the test but it had also been sat for 40 min turned off whilst they did all the other bits. Will book it in for next saturday and give it a run up the motorway to get it toasty and see if that helps.

[Red Devil]

OP, re the thread title the way to find out is to use this flowchart - http://www.motinfo.gov.uk/htdocs/m4s07000309.htm
If the answer to the EXACT match question is yes, then it should be tested to the limits listed on page 79 of this:
In service exhaust emission standards for road vehicles - Eighteenth edition - https://www.gov.uk/government/uploads/system/uploa...
If the answer is no, then follow the test requirement which differs according to the date of registration/first use (i.e. in Japan, not the UK).

I get this all the time as the specific model of my car was never officially sold over here. They are all grey imports.
A surprisingly large number of testers are unaware of this and thus fail to follow the instructions in the manual.

[Daston]

Got the retest later today, just planning the route I can take to get to the garage. It is 1 mile away from my house, so far I have around 30 miles of B roads planned out That should get it hot enough.

[Daston]

Retest done....failed again

We got the CO% down to 2.3% (pass rate is 0.200%) on idle it was 9.6% with hydrocarbons at 2250!!! I seems to be over fueling a tad.

[Shnev91]

If ur car was 2 years older 3.5 would be the pass rate. Thats rotten luck.

[Daston]

Shnev91 said:

If ur car was 2 years older 3.5 would be the pass rate. Thats rotten luck.

Yep

Going back today for another attempt, this time going to try it with the airpump connected and disconnected to see if there is any difference. Failing that will be on the horn to the engine builders to see if they have any ideas.

Want to get it sorted before Japfest!!!!

[Riknos]

Daston said:

Shnev91 said:

If ur car was 2 years older 3.5 would be the pass rate. Thats rotten luck.

Yep

Going back today for another attempt, this time going to try it with the airpump connected and disconnected to see if there is any difference. Failing that will be on the horn to the engine builders to see if they have any ideas.

Want to get it sorted before Japfest!!!!

Stupid question but is the cat knackered?