Help & advice C5 Cat please help

CITROEN-SUCKER · Post by **CITROEN-SUCKER** » 08 Sep 2005, 04:55

Hi all hoping someone might be able to shed some light on this......
Got a fault with antipolution system on my C5, no problems me thinks.. Take it to the dealer they say cats dead(poor thing)but to be safe get the oxygen sensors done as well just short of £1000[:(] but why get the sensors done if they tell me the cats dead so.... Got a cat done a Kwick fit for half dealer price, Great... that was 3 weeks ago now Antipolution fault again... Well took it back to the dealer. No problem full report sensors fine engine fine (thanks God)[:D] but the cat is no good....So back to Kwik Fit they checked it and seems fine (But what do the dealers know as they don't fit too many says Kwick fit) Its back to the dealer on Friday and I think I know what they will say. So who do I trust Kwick fit say cat is fine Citroen and the car say it isn't what do I do? [:(]

wheeler · Post by **wheeler** » 08 Sep 2005, 05:11

you need to find out the readings from the upstream & downstream oxygen sensors when it is on the diagnostic equipment.the upstream sensor readings should constantly fluctuate between approx 100 & 800 mV (when engine warm),it doesent matter what the downstream sensor reads (between 100 & 800 mV though) as long as it stays constant,if the reading fluctuates like the upstream sensor then the cat is no good or there is an exhaust leak.