Emissions Fail

[lune]

Ahhhh,
Whats going on!! Took me car for MOT and sailed through everything apart from bloody emissions
Apparently CO much to high and bloke reckons it's prob the CAT's that are knackered!
Anyway I've stuck a new lambda sensor on in the mean time and hope this solves it
I dont have the exact readings but the bloke said the CO was way high, the HC's were high but the lambda was low? I had it serviced 2 month ago and it threw no codes and Jas checked codes at Leeds 2wks ago so what could it be guys?
I asked the tester if it could have anything to do with it being chipped and the bloke said it should have no problems, which was what I was thinking anyway.
Could F**ked CAT's be the answer or am I just looking on the dark side? I've changed the lambda sensor and I'll wait and see if this helps.
Any ideas in th mean time would help me sleep better

Cheers
Ben

[merlin's S4]

I know this may sound like a bit of a long shot but the garage I use swears by the Forte additives! They've used the "Forte Gas treatment" on many vehicles failing on CO emissions and after a short drive most have gone through! The stuff usually costs around £12 but if you can't find it locally (they only distribute it through garages) then try www.camskill.co.uk or search ebay for some!
Hope this helps!

[dan_b]

What age is your car? How many miles have you done?

[lune]

Cars 1996 with 140k miles and FASH

Cheers
Ben

[rotoryboy]

Give me a bell, It will pass at our guy

[S2central.net]

Mmmm yes right well... as for actually resolving the source of problem, it could be one or more of the following :

Dead CATs
Bad lambda probe - they need changed every 60k
Excessive fuel pressure or faulty FPR could cause it in theory
Who did the chip upgrade as a crazy rich mixture could be the problem ?
Other things that make the ECU inject more fuel are faulty coolant & air temp sensors
Also you might just have a faulty MAF


Paul

[Henka]

You know what - CO will drop drasticly if you ad about half a liter of ethanol (or just fill some E85, about 10-15%). It's not a cure, it's just a quick fix. I never go to MOT without it. It won't do all that much for HC but CO will drop dramaticly!

[S2central.net]

Now there's a trick alright... Would it get a deCATTed car temporarily into typical CO levels for having CATs ? I've never looked into this before ....

Paul

[lune]

Mmmm yes right well... as for actually resolving the source of problem, it could be one or more of the following :

Dead CATs
Bad lambda probe - they need changed every 60k
Excessive fuel pressure or faulty FPR could cause it in theory
Who did the chip upgrade as a crazy rich mixture could be the problem ?
Other things that make the ECU inject more fuel are faulty coolant & air temp sensors
Also you might just have a faulty MAF


Paul

Dead CAT's- (How likely?) They don't rattle or rasp etc.
Bad lambda-Has never thrown a fault code, but changed it for re-test anyway (wait & see for results
Fuel press or FPR- Would gen any other codes or cause relating probs? As car is otherwise sound
MRC custom chip so doubt this could be a prob
Again sensors and MAF's tend to have other symptoms also and sometimes throw codes.

Looking like CAT's more and more, gonna try that Forte gas treatment sounds like ledgendary stuff, cant argue for £10
I can deal with the emissions problem, just don't like havin things wrong with car and thought this may be a symptom of an underlying problem.

Cheers for all help guys

Ben

[S2central.net]

It won't be chips for sure... I wouldn't consign CATS to the bin until its retested. IME there can be running problems with lambda and MAF long before a fault code is registered... sometimes never... Same is true for temperature sensors - silly Motronic can only detect s/c or o/c conditions.

CATs don't have to be rattly to be faulty - they may just be tired out... though with your mileage the original items should be OK.

Good luck - hope the new lambda cures it - did you fit a genuine VAG/Bosch item or an elcheapo replacement ?

Paul

[lune]

Right failed again
No fault codes new bosch lambda probe.
Readings are as follows:
CO 4.5% (high)
Lambda 0.857 (low)

This is also after running some forte gas treatment through the system.

About 3months ago I had a prob with inlet temp sensor and took it to garage to have it fault found, the garage fixed the wiring and gas tested the emissions to double check everything. The bloke in the garage remembers the emissions being spot on, the only change to the car since is the re-map, but I have my doubts that this could cause any problems.
Any more ideas?

Cheers
Ben