Omega Owners Forum

Omega Help Area => Omega Electrical and Audio Help => Topic started by: mantamania on 04 June 2010, 19:30:07

Title: Fault Code 0420
Post by: mantamania on 04 June 2010, 19:30:07

Hi All,

I have a 2.2 petrol Omega and every now and then  my engine light comes on and when I read the fault code it gives me "0420 Catalyst System Efficiency Below Threshold (Bank 1)".  I have searched the forum but could not find it posted on here.  Can some one please give me an indication as to what causes this fault.  Car has just had its MOT and passed so no emission problems. Thanks

Title: Re: Fault Code 0420
Post by: Welung666 on 04 June 2010, 22:34:31

The easiest fix is to move the first lambda behind the main cat, the proper fix is a new cat. Have a look in the maintenance guide index, there is a how to, it's for a V6 but you've only got one to do ;D