Missus car is in for MOT test tomorrow, and I reckon the emissions test will be a close call - full decat, ceramic manifold, straight through 3" stainless system etc.
I am wondering if it is more likely to pass emissions test if hot or cold - it's likely to be pretty cold at 9am tomorrow when it's in, and garage is only 1 minutes drive away - so if likely to be better cold, will not warm up.
Any opinions on this?

 

MY 95 WRX WITH DECAT PASSED WHEN RUNNING RED HOT. HAMMARED TO THE MOT STATION AND LEFT TICKING OVER WHILE CHECKING OTHER POINTS OF THE MOT.

 

Needs to be at the very least warm, cos if it's cold it'll be as if it's runing on choke, therefore the amount of fuel being injected will be massive, hance extremely high emissions, so, hot is preferable, it's not bad if the test is the first thing to be done either, although with a full decat, assuming it's a car that should have a cat test it'll probably fail anyway!

 

i was told the cat dont work until it get up to 400 degrees is this a goverment make money i always take mine in when hot and it always passes

 

doubt if you will pass, mine did not.
I had to put centre cat on.
I ve actually left it on because could not feel much difference in power, and now a bit quieter.
Aggs

 

How did it go Sulli,
if it failed, where are you, I have something thatmay help!!

 

It failed - CO emissions way high on all tests (exhaust too noisey too).
Unfortunately it's not just a CAT I need, but a standard manifold also(the missus's car is a 1.8 Focus) as the car has a full Kamikaze race header which is much longer than the original manifold.
Having a bit of a job sourcing the stuff so far.