Mot Not Passed!!!!

gibby250983 · April 25, 2012, 02:05:18 PM

failed on too much CO2??? never heard of that but it did any suggestions why this is the case??

clive · April 25, 2012, 03:08:34 PM

What car is it ?

GrimR33per · April 25, 2012, 05:13:19 PM

http://www.rx7club.com/showthread.php?t=869823

A good read for you

m1tch · April 25, 2012, 05:20:37 PM

Quote from: gibby250983;820947failed on too much CO2??? never heard of that but it did any suggestions why this is the case??

Its a common issue on RX7s, usually a yearly battle to get the CO2 to be ok to get it past the MOT lol

gibby250983 · April 25, 2012, 05:23:13 PM

1994 fd3s......thinking it might be the cat..... started it up and something that looked like a stone was glowing..... once it cooled down found out it was a bit of my cat...oooppppssss so looking to change that and gonna change the plugs and o2 sensor..... see if that helps!!

what ya think

gibby250983 · April 25, 2012, 05:24:16 PM

Quote from: m1tch;820965Its a common issue on RX7s, usually a yearly battle to get the CO2 to be ok to get it past the MOT lol

but what is usually done to get it right!!!??

gibby250983 · April 25, 2012, 05:24:46 PM

Quote from: m1tch;820965Its a common issue on RX7s, usually a yearly battle to get the CO2 to be ok to get it past the MOT lol

but what is usually done to get it right!!!??

Prof · April 25, 2012, 06:00:52 PM

If it\'s an FD, then the test is only for CO (carbon monoxide) and HC (HydroCarbons). If it\'s post 92/93 or 96 for an import then it should have a cat and will consequently be tested to the more stringent emissions test.

Normally a CAT and working air pump with a properly tuned non misfiring engine should be enough to pass the test.

Things people often do to help get it through:

Run some Redex or similar through the injectors to help clean them
Clean or replace the air filter
Make sure the spark plugs are in good order, replace if necessary
Make sure the car is warmed up thoroughly for the test - the MOT tester should do this and they aren\'t doing the test properly if not
Make sure there is no air leak in the exhaust as that can skew the readings.
Make sure the car is idling smoothly - no vacuum leaks, no misses, good fueling.

The O2 sensor on FC/FD is not used to adjust idle fueling, only on cruise between about 1500-3000 rpm so replacing it won\'t make a difference to the idle emissions figures, unlike with many other cars.

gibby250983 · May 01, 2012, 07:00:52 PM

Quote from: Prof;820975If it\'s an FD, then the test is only for CO (carbon monoxide) and HC (HydroCarbons). If it\'s post 92/93 or 96 for an import then it should have a cat and will consequently be tested to the more stringent emissions test.

Normally a CAT and working air pump with a properly tuned non misfiring engine should be enough to pass the test.

Things people often do to help get it through:

Run some Redex or similar through the injectors to help clean them
Clean or replace the air filter
Make sure the spark plugs are in good order, replace if necessary
Make sure the car is warmed up thoroughly for the test - the MOT tester should do this and they aren\'t doing the test properly if not
Make sure there is no air leak in the exhaust as that can skew the readings.
Make sure the car is idling smoothly - no vacuum leaks, no misses, good fueling.
The O2 sensor on FC/FD is not used to adjust idle fueling, only on cruise between about 1500-3000 rpm so replacing it won\'t make a difference to the idle emissions figures, unlike with many other cars.

it is a import, 1994 FD3S...... and i have been looking on this web site and found that it shouldnt get a emissions test due to it being an import.

also found that the DVLA dont have any readings of a emission readings!!

think im getting confused... but can you clarify please!!!

m1tch · May 01, 2012, 07:12:14 PM

I believe its 3.5% CO and 1200 PPM, what were your readings and we can see what might need tweeking.

Do you have any mods or a power FC fitted?