MOT failure

Brighton-Rex · January 14, 2012, 04:29:44 PM

Hi guys,

Just took my 92 FD for its MOT but it failed for the first time on emissions, they are meant to be below 3.5% but were 7%.

The car has an Apexi PFC fitted but passed last year with only 2.4% and i havent changed anything or modified the car further since then.

I read on here i could adjust the settings for fueling on the PFC to get it through the test but why would these have changed so much?

If i can get it through an MOT then that\'s a start but also concerned about the cause of the increase since last year, any ideas? Could i be damaging something by running the car like this?

Any advice would be great,

Ta

m1tch · January 14, 2012, 04:56:42 PM

Is it an import? Do you still have a cat or air pump? Might be something like an O2 sensor being slightly off causing it to fuel slightly differently

Brighton-Rex · January 14, 2012, 05:10:16 PM

Yeah its an import. I haven\'t removed cat or air pump no, does my car have a cat then? As I know it\'s exempt from the full emissions test due to the age.

m1tch · January 14, 2012, 05:20:43 PM

If it was a UK spec FD then it wouldn\'t be exempt, but as its an import its ok, which is good lol it should have a cat, the UK spec cars have an extra cat on the downpipe, its odd as my FC with just an air pump (no cat, hasn\'t been fitted for over a decade) had a CO of 0.18%.

What sort of fueling do you have? Is it standard but with a PFC?

This might help, it seems that you just need to temporarily drop the PIM

http://www.mazdarotaryclub.com/forums/showthread.php?t=65458

Brighton-Rex · January 14, 2012, 05:49:48 PM

Has pfc with twin apexi filters running on standard fuel pump and injectors.

Yeah I could do that for MOT I think so might be ok for pass but I\'m worried about damaging something by running so rich, something must have stopped working properly since last year as CO was much lower.

m1tch · January 14, 2012, 05:54:40 PM

Does the PFC show what the O2 sensor is reading at idle? It might also say on the MOT printout, if thats out only slighly then it can cause all sorts of emission issues, also what oil temp does it say the car was at during the test? Perhaps the cat wasn\'t up to temperature, I know some owners put in \'cataclean\' before the MOT which apparently helps.

TRIND-FD · January 14, 2012, 06:12:26 PM

http://www.mazdarotaryclub.com/forums/showthread.php?t=65458
Might help looking at my video, and a bottle of cataclean.

Brighton-Rex · January 14, 2012, 06:14:50 PM

The printout says O2 was 0.24%

Doesn\'t say oil temp but I saw it was at running temp when I got back in it straight afterwards so was prob warm enough.

With the tip on the fuelling setting on pfc and the cataclean then test might be ok, but Im more concerned about an actual fault that I might need to fix as don\'t want to cause any running probs etc and that CO figure seems quite high compared to last years.

TRIND-FD · January 14, 2012, 06:22:39 PM

My car and my sons car both fail on the same symptom as yours every year, 5 years for my sons car. My engine has 4000 miles on it.it failed with 10 miles on it.

Some cars pass fine. Just drop you pim volts , pass your mot , put the pim volts back up and then enjoy.

rising son · January 14, 2012, 06:33:21 PM

silly question but was the emmisions tested at running temp or was it tested from cold?

Brighton-Rex · January 14, 2012, 06:44:12 PM

Quote from: TRIND-FD;807144My car and my sons car both fail on the same symptom as yours every year, 5 years for my sons car. My engine has 4000 miles on it.it failed with 10 miles on it.

Some cars pass fine. Just drop you pim volts , pass your mot , put the pim volts back up and then enjoy.

Ok well that\'s reassuring as was worried I might damage the car driving it like this. I\'m pretty sure I can sort the mot either way but was just suprised the readings were so different to last year. The car seems to run fine and hasn\'t been using extra oil and tbh the fuel comsption seems normal too so perhaps it\'s nothing.

wolfie1 · January 14, 2012, 07:30:39 PM

maybe the mot equipment is due for a calibration in the next few weeks or they have a dirty co2 filter on the machine or the water trap was full cause that would give you a false reading

m1tch · January 14, 2012, 07:47:21 PM

If its any consolation, my FC is running epically rich, it makes your eyes hurt when its warming up before you drive off

adib · January 14, 2012, 10:58:36 PM

did they put it on a cat or noncat setting

m1tch · January 14, 2012, 11:09:07 PM

Quote from: adib;807191did they put it on a cat or noncat setting

The non cat test is a max CO of 3.5%, so it seems they have.