Absolutely gutted failed my retest today! I had some radiuses that needed doing they passed without a problem, and then the only thing left was emissions!

The engine is R1 2006, a caterham exhaust with a built in cat, the cat was replaced and is a brand new ceramic cat only about 15 miles driven on it to get to the test centre. The cat was red hot, the tester even allowed us to rev it a fair bit previous testing and holding at 3000 for around half hour.

My results were:

Fast Idle Test:

CO

(0.20 LIMIT) 0.03 Pass

HC

(200 LIMIT) 119 Pass

LAMBDA

(O.97-1.03) 1.278 FAIL

Natural Idle:

CO

(0.30 LIMIT) 0.00 Pass


Just cant get the Lambda down whatever I tried I went in there with a set map ended up about -23 on fueling and god knows where my idle screw ended up! I was winding it and out to no avail!

Hopefully someone can shed some light on this for me as I feel pretty defeated!

Cheers Coopz

hi

have you got a power commander fitted?
on all our cars this is a must for the emmisions for the IVA.a bike engine will not pass just by putting a cat on it.

if you need any help just ask

cheers danny

Sorry danny, I didn't make that clear yes it has a power commander fitted, I ended up at -23 fueling between the fast idle rev range and natural idle.

High Lambda reading is often down to an exhaust leak , even a very slight one will cause problems . Another cause is a very weak mixture, it may be worth richening it up slightly

I would suspect you have it a little too weak, or you have an exhaust or inlet manifold leak, OR the tester hasn't got the test probe far enough up the exhaust (& believe me that happens more often that you might think - if the probe isn't right into the exhuast it can draw oxygen from the fresh air around it!)

So make sure you have no leaks, get it down to a friendly MoT station & richen it up a bit then check & play about with the mixture - lambda too high = weak, lambda too low = rich, aim at getting lambda right & the other figures will almost certainly come into line, if you have it running for quite a while at 2500 - 3000 revs watch your engine temp, it can climb very rapidly!

Hi mate, i had exactly the same problem with my 2003 R1.
As the guys have already said, i was running -20's in my power commander which was way too weak.
I ended up with around -10's, making the mixture richer therefore lowering the lambda.

Hope this helps and good luck.

Thanks for all the info guys, going to go over the exhaust and use exhaust putty on the slide joint as i suspect there might be an air leak. Sounds like i might be running a bit lean I found when I added fuel it pushed the HC out! How much should I concentrate on the Idle screw also?

Another theory I have is i'm running a pipercross filter due to bonnet clearance, which means I'm running the AIS system on a small breather of its own instead of into the airbox. Could it be that its sucking in too much air pushing my lambda reading up? I'm tempted to block this off see if I can bring the lambda down but still stay within the limits on CO and HC.