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Discussion Starter #1
Our beloved very tidy 2.0 8v Laguna has failed its Mot on emissions - nearly everything tested was above the limits. Could anyone guide me as to whether this is a Catalytic converter issue or something else? I know it needs a set of plugs as it has been a little lumpy occasionally but other than that it's been well maintained and looked after... has a very rare and minor misfire done my cat in? Thanks all
 

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Could well be the Lambdas, there is two on the Lagunas, mine both needed replacing for the mot,better hope it's not the cat, they can get expensive,.
 

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Discussion Starter #4 (Edited)
Thanks Gents - Unlikely to be fuel as i belive the dodgy batch is (fortunately) affecting more the southeast than the southwest. Cat isn't too bad if that's what it is. Someone is offering them for about £65 new and delivered on Ebay at the moment. I'm handy with the spanners when needed as an ex kit car fiend which helps a bit!!. Hadn't thought of Lambda's but may have to get it plugged in to find something that specific - I have also spoken to a RAC patrol mate who reckons there is some sort of cat cleaner fuel additive out there that gets his Toyota Carina (YUK!) through its emissions each year - if that and some new plugs won't sort it i think i'm going to have to get some bod with a computer to analyse it and see what specifically is causing it's depression! My Mot station reckoned that the car - 1998 + less than 100k miles was a write off and I should scrap it!!!
 

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Emison failure

Hi Chris - knowing why it failed the emisssion test would be a good help. Can you find if it was due to excees hydrocarbons, CO,CO2 , or oxygen levels - good test equipment will give a read out of all gase present.
 

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Hi, a misfire can damage a cat but as someone else has already said, the readings you got would probably give an indication of where to look at first.

My 1997 Laguna was on 145,000 miles on the original cat and lambda and always passed the emissions without any problems and well within the limits, so I'd give it a service with plugs / air filter change, run some injector cleaner through it, warm up the cat with an enthusiastic drive and take it for an emissions test at your local freindly garage and see how it compares.
 

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If you could post the readings that you have,then it will give us a clue as to whats wrong.

It could be something simple like a blowing exhaust or faulty Lambda sensor.I suspect your car would only have one(before the cat),and they are not expensive.:)

The worst case scenario is that the cat might be damaged,but the price of cats has come down quite a bit recently and they are certaintly not the crazy prices that they were when the technology was still new.

The slightly poor running could also cause problems with emissions tests,but if you post the readings we'll know more.You should have a Lambda reading,a CO reading and an HC reading for both fast idle and idle.:)
 
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