Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Osaze on 15 June 2016, 17:51:58

Title: CO emissions MOT fail
Post by: Osaze on 15 June 2016, 17:51:58

Hi, so my '96 2.0 X20XEV estate hasn't got through on emissions. The garage have changed spark plugs, cam cover gasket (they said it was leaking) and have put in fuel (Petrol Magic) and oil (Stop Smoke) additives.
Latest results read
1st fast idle test-

CO 0.59% FAIL
HC 161 ppm PASS
Lambda 1.027 PASS

2nd fast idle test-

CO 0.61% FAIL
HC 131 ppm PASS
Lambda 1.026 PASS

Natural Idle test

CO 0.5% PASS

A new cat is probably the brute force method to get it through unless anyone has other suggestions?

Title: Re: CO emissions MOT fail
Post by: Entwood on 15 June 2016, 18:05:51

Before you splash out on a cat check for exhaust leaks !

The probe they stick up the exhaust gives completely different readings to the lambda sensors that the engine ECU uses, simply due to the 8 foot difference in distance between them !!

As the lambda values are good you probably don't have a leak, but still worth checking, once you've done that then give it a bloody good italian tune up ... drive it like you stole it for 20 odd miles using the full range of revs, right up to the red line.

You are not failing that badly IMHO .. the limits are 0.5% at idle and 0.3% at fast idle, if the cat had failed then the figures would be much higher AND the HC would probably be out-of-limits as well.

I'd be thrashing it down a motorway for 20 miles then retesting it if it was mine .. :)

Title: Re: CO emissions MOT fail
Post by: Marks DTM Calib on 15 June 2016, 18:18:38

I would agree regarding the exhaust leaks if the lambda was off  :y

Is the engine up to temperature ok and stat ok?

Title: Re: CO emissions MOT fail
Post by: Bigron on 15 June 2016, 18:53:00

Sorth trying "Cataclean"?

Ron.

Title: Re: CO emissions MOT fail
Post by: Osaze on 15 June 2016, 19:00:07

Ok thanks all

Quote from: Marks DTM Calib on 15 June 2016, 18:18:38

I would agree regarding the exhaust leaks if the lambda was off  :y

Is the engine up to temperature ok and stat ok?

Yeah as far as I'm aware.

Title: Re: CO emissions MOT fail
Post by: Doctor Gollum on 15 June 2016, 19:54:51

Fill it with V power and a bottle of Wynns fuel treatment, rag the living daylights out of it, (aim for 200 miles from that tank).

Fit a new airfilter on the morning of the retest along with a fresh tank of V power and Wynns, and make sure the engine is HOT when presented.

Title: Re: CO emissions MOT fail
Post by: frostbite on 15 June 2016, 22:53:19

My xev just squeezed through the test they also had to do it twice but raised the idle a tad on the second to get it through