Emissions Fault... PLEASE help :-(

[Anigmalistic]

Hi guys,

Sorry for the desperate plea in the title but I'm really on the verge of crying here.

Vehicle is a 1998 1.9 Roadster belonging to my wife which we've owned since 2013. It failed it's MOT every year since about 2007 due to emissions, and each time there was a re-test after some fuel cleaner and a blast round the block which always passed.
Since we owned it the same thing happened, and each time the fail got more severe followed by a more marginal pass. Eventually last year they told me that it was too far gone and needed a new cat. This made perfect sense, the cat degraded further and further until it was fully gone.

We got a new cat and it passed. I asked him whether it was still a marginal pass and he said no it's exactly what we'd expect now, so as far as I was concerned that was problem fixed for another 5 to 10 years.

Only it's failed again. My wife only does short journeys round town so I assumed it might be a clogged cat, but a dose of cataclean and a REALLY good blast later and it's still failing, and not by a little bit, CO limit is 0.30 and ours is putting out 0.60. I asked whether the cat could have gone again and they said that it's unlikely to be the cat as those readings are higher (by a long way) than even an older car which didn't have a cat at all.

The thing is the Lambda and HC readings are well within limits, and there are no engine management lights on so it wouldn't appear to be overfuelling, the MOT testers had some scary sounding guesses such as valves sticking open, head gasket (but that was changed the year before last) or "some underlying mechanical issue" but really they're stabbing in the dark. The only other thing which I know is going on under the bonnet is when the guy changed the head gasket he said there were some little breathers on the injectors which were perished making the car smell of fuel after it'd been driven, but he reckoned if anything they'd make the car run lean and based on the other readings from the probe it doesn't look like this is causing it.

I'm at the point of despair, if something's broken I can fix it but I don't know where to start. I don't have the money to just start changing things willy nilly, it doesn't sound like the cat has simply failed again so I'm stuck.

If anyone has experienced anything like this I would really appreciate your input. The car is mechanically sound other than that, and was a wedding present to my wife so scrapping it would be a travesty and really isn't on the cards... but equally it can't just sit about on the drive if I can't get it fixed...

Thanks in anticipation,
Pete.

 

[Grumps]

Sorry to here this Pete. I have a 98 2.8 and have the same issue. Mine reads 0.54 every MOT and has done for 7 years. I've owned it for 3-4 now. I was in the same dilemma last year as took it to a different mot station and they failed it. My usual MOT station let's it go. Don't get me wrong if there's anything dangerous or in need of repair he will fail it instantly but he's OK with my emissions issue. It will have to be addressed at some point but for the minute I make do.

 

[Anigmalistic]

Hi Grumpy,

Thanks for the reply. Yeah I did consider that option, I have another MOT tester who does my Audi as it has a decat... he's a bit old-school he says that an MOT was always about safety and doesn't really believe emissions should be a part of it. With that in mind he'll still do the MOT properly but will overlook emissions (within reason)

Thing is, it's not really a "fix" as such... if that's my only option I'll take it, but I'd really like it to be all working properly and above board.

Anyway if you find a solution before I do I'd love to hear about it!!

P.

 

[jonco]

Hi - I have the '98 M44 and had a similar history on emissions which deteriorated to .5+ CO last MOT.
Injectors changed - no significant difference. Cat changed and problem solved.
What cat did you fit budget or quality?
Low usage around town will not help especially if you are using low quality fuel and /or minimum octane fuel. You will gum up a few things under those conditions.
Does the car run evenly?
Have you had the codes read?

 

[Anigmalistic]

Hi,

Thanks for the reply.

It was a budget cat which did fix the problem last year, I know it's not going to last nearly as long as a high quality cat but less than a year seems extremely short, and the testers comments about it being bad even for a car with no cat at all made me think that it's probably not the cat, or that some other problem is destroying the cat.

I know the driving my wife does isn't ideal, but when I took it back in for a retest this time I'd blasted the crap out of it with cataclean on board... it barely made a difference.

Car runs evenly and smoothly... beautifully even, it feels and sounds very strong and smooth for a 20 year old engine!

I haven't had codes read, there is no warning light on at all... will codes still come up even without throwing a light on?

 

[t-tony]

Cats for this years of car do not have to be "type approved" and as such are usually of very poor quality and you will be lucky to get much more than 1 years use out of it. It looks very much as though the cat isn't up to the job I'm sorry to say.

Tony.

 

[EnthuZiaZT]

This may be of no help, but have you thought about Terraclean. Several cars have been done on Wheeler Dealers and it seems fairly good. Doing short runs out, as you say your wife does, will not do the engine any good. But I would have thought that something is disabling the CAT.
It might be that the engine is burning a little oil but you have not mentioned this so if it is, it has not become an issue for you. The only other thing that you might do that would help is take the throttle body off and clean it thoroughly. Then give it a really good blast down the motorway, 70 MPH in 4th gear for 5 or 6 miles should do it.

Mike

 

[Anigmalistic]

I must admit my first thoughts are still that it's the crappy budget cat that's failed already... the thing is the tester seemed very sure that the emissions were so far out that a dead cat alone wouldn't cause them... what I don't want to do is spend £400 on a high quality cat, only to find that there IS a running problem of some sort and whatever is being dumped down the exhaust kills that one too...

I don't think it's burning oil, there is no blueness or smoke whatsoever and it's been on the max line the whole year.

I think the terraclean stuff does the same job as cataclean, I only chose cataclean because I've heard it come very highly recommended by professional technicians.

I'll try replacing the injector breathers to see if that makes any difference and see if I can get a free replacement cat out of Euro car parts... it won't feel as bad if it's free!

 

[5harp3y]

Sounds like you need to rag the crap out of it before the test.

Like get it proper proper hot and get the fat working. No way a new cat should be failing even a crappy aftermarket one

You changed the plug recently as you might not be fully igniting the mixture

 

[jonco]

................. the thing is the tester seemed very sure that the emissions were so far out that a dead cat alone wouldn't cause them... what I don't want to do is spend £400 on a high quality cat, ........

As previously stated my CO emissions were that high and resolved by cat change. I agree I would not spend that money on a cat. I have gone for a Re-act from Eurocarparts again with a 2 year guarantee. If you use good quality fuel and give it a regular `blast' to compensate for `town driving' they will last longer a lot longer.

 

[pgunter]

When my old Ford Zodiac used to fail.. A bottle of Redex and a good fuel.. Long run up and down the motorway and straight into the mot station for a timed appointment so it does not cool down too much. Always used to pass. Cold pipes are annoying.

If you are local to Winchester I would stick my code reader on for you. If not I am sure someone on here could for you. Normal charge is a coffee lol..

 

[Redline]

Not an expert but is sounds like a fuel mixture issue somewhere so I'd start looking for obvious problems before blaming the cat. Could be lots of reasons for that or even a combination of reasons but its essentially not enough air or too much fuel. Is your fuel consumption what you'd expect for the mileage your doing?
Its possible the electronics will try and overcome one problem by changing something else to compensate.
Probably best to start on the basics, from the air filter, splits in pipes, checking any error codes for cam-shaft, airflow sensor, etc and then on to injectors or other problems. A worn injector will let in mire fuel than the ECU is expecting for example. Have the injectors tested if nothing obvious is found.

 

[andyglym]

Loads of positive reports on Terraclean as stated so could be an option? Mines a 98 2.8 and passed ok but I do use only RON97 fuel and I gave her a treatment of Forte Injector cleaner and took her for a long high speed run. Made a differance. May be an option?

 

[Grumps]

Sounds like you need to rag the crap out of it before the test.

Like get it proper proper hot and get the fat working. No way a new cat should be failing even a crappy aftermarket one.
You changed the plug recently as you might not be fully igniting the mixture

I did that last year and the reading was exactly the same. I think I probably ort to change the cat.

 

[pgunter]

I did that last year and the reading was exactly the same. I think I probably ort to change the cat.

I think @jue1 might have words with you for that .. at least its not the Dog..

 

[t-tony]

Pete, can you post a picture of the emissions failure sheet please?

Tony.

 

[Grumps]

Pete, can you post a picture of the emissions failure sheet please?

Tony.

It's a similar reading to mine Tony, if I recall we put it down to a lambda or the cat? I really ort to get it addressed.

 

[Dino D]

I've read plenty of complaints about budget cats lasting a few months.

A proper cat is expensive so maybe try a second hand cat from a car that's known to be running ok @spurs fan in a coupe might have one he knows to be good.

 

[t-tony]

I see them fail regularly. The test result is a good indication of where the fault lies.

Tony.

 

[spurs fan in a coupe]

I've read plenty of complaints about budget cats lasting a few months.

A proper cat is expensive so maybe try a second hand cat from a car that's known to be running ok @spurs fan in a coupe might have one he knows to be good.

Thanks @Dino D

I'm always a bit dubious about selling second hand cats, as I have no way of know how good/not they are, but yes I have a few available.

OP where you based?