My W Reg (2000) 1.2 punto has failed it's MOT on CO emissions. We had the same problem last year and sent it to the local FIAT dealer who eventually fitted a new ECU, it went back to MOT test centre failed again. Then the FIAR dealer put it through it's MOT which it passed (very odd).

Now it's gone back to the dealer with the same fault as last year a CO emissions reading of 0.6 on the high revs test. The dealer says that they've replaced the lamda sensor and cat convertor (from a donor car) which slightly lowered the emissions but not enough for it to pass.

Now they want to try a new ECU (although they replaced it last year). If it's not that they are saying they need to start taking the engine apart, and have mentioned something about the head gasket.

Has anyone got any ideas what could be wrong? I don't trust the dealer at all as they said they'd fixed the same problem last year when they hadn't.

Sorry the post is so long

air leak in exhaust system, or engine not reached correct testing temperature

So are they talking rubbish about the head gasket?

yes, you dont take engine apart to check head gasket anyway, there are tests that can be done to see if that is gone

does the fact the puntos don't hold their revs on the high rev test not something to do with this??

seems nuts (well fiat dealer actually) that they replaced the whole ecu (£££) before a lamda sensor (still best part of £200 for some of them).

I would go with the temp thing, I seriously seriously doubt headgasket, maybe piston rings, but that is not a common thing, very very very rare infact for them to go on these engines

Won't the garage accidently connect the exhaust probe up to the wrong car that they know will pass the emissions test??? My bro had that happen to him, fortunately there was a freelander next to his car in the garage and the tester obviously got muddled up!!

Off topic, but my old bosses BMW 7 series had 2 cats, and one of them was knackered, so every time it needed MOTing they had to use a particular exhaust pipe to get it through!
I don't know what the problem is here, but it sounds like a lot of work for something that should be relatively simple.
H

faster4_tec said:

does the fact the puntos don't hold their revs on the high rev test not something to do with this??

seems nuts (well fiat dealer actually) that they replaced the whole ecu (£££) before a lamda sensor (still best part of £200 for some of them).

I would go with the temp thing, I seriously seriously doubt headgasket, maybe piston rings, but that is not a common thing, very very very rare infact for them to go on these engines

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Gotta be worth the belt down the motorway for a couple of junctions & take the test 9 times out of 10 this fixes emission problems!

Does the garage youve taken it to have a water trough out back for their horses that they rode into town on?(cowboys)
If they want to try a new ECU tell em to do so at their own exspense:slayer: as they only replaced it 12 months ago ! Personally, id take it for a thrash to get it up to temp., as its worked for me before now

Thanks for all the advice.

The worrying thing about this is I'm taking it to a major FIAT dealer - the only one in the large city I live in

It's going back to my regular mechanic tomorrow who I trust completely. I think it might be a temp problem so will take it for a long drive.

As has been said here, a good HARD drive might well help.

I used to sell cars with a friend and a lot of them we had to MOT had been sitting around for a while, or only driven short distances and/or in stop start traffic.

What is neede is a really good blast at high revs. I was told to take a car down a bypass and "drive it like I'd nicked it".

So, I ragged it up and down the bypass in 3rd gear, got back, tesed it straight away and it passed!

I know this won't be easy to do if you live in a city, but it's worth taking out onto an open road and blasting it!!!

Just phoned Dealer, what a surprise it still failed it's emissions with a new ECU - I knew it would.

So am definately taking it for a long hard drive before the MOT. I think it's pretty ridiculous that the dealer doesn't know that this is a recurring problem with puntos and recommend it.

Thanks again everyone

what dealer is this?

Other halfs Hyundai Pony once failed MOT on emissions and the solution was offered as a new Cat @ £700 Actual solution was redex (£3-£4) & a weeks worth of driving it like you stole it (aka italian tune up)... and warm the car up for half hour prior to retest, as cats only work properly when fully warm Let us know how you get on won't ya...