Citron Xsara Vts Problem Any Idea's ?

[Guest anto_harris]

hi guys iv just brought a 51 plate citron xara vts 2.0 16v and it has qute a bad missfire and the on bord computer says its the cat ?

 

any ideas what this could be i was thinking mabe the lamba sensor ? but its a pretty new car so it shouldnt really be this should it just done over 100,000 ?

 

many thanks new boy ant :(

[techbod]

check the state of the spark plugs/leads and coil packs a catalyst doesn't cause a misfire unless its blocked and you would know if it was so the cat is doing its job because a misfire would cause uneven fuel/air mix and the o2 sensor would give a fault