Engine management light on on my daughters 2001 Fabia 1.4MPi 8v

Went to Skoda dealer for diognosis and was informed needed new cat (£816.00 fitted :eek:). We were given the report of the following codes: P0130, P1141, P1176, P0140, P0130

I fitted a new (non Skoda) cat but it failed emissions test.

Print out from my local garage is as follows:

CO level 0.77%, HC level 173ppm, CO2 level 13.90%, O2 level 0.54%, LAMBDA 1.00, Oil Temp 95c.

They say the problem is with the new cat. I phoned another local garage and they agree based on these figures.

I phoned the cat people who wanted the figures faxed through and after looking at them say the probem is not with the cat but probably with the coil pack or Mass air flow sensor. There is a slight lumpyness when idling but I changed the spark plugs and the ones that came out looked lovely, grey - light brown, not suggesting car running rich.

So off to another garage and diagnostic test and on the way the light came back on the dash (after being reset by Skoda). After reading faulty Lambda and checking it he said the front lambda sensor was not switching. This guy said that it looked like faulty cat but wouldn't condemn it untill Lambda sensor changed. So forked out more money and fitted the new front sensor. Went back for reset and check and guess what? No different!

His test results after replacing the Lambda:

Hydrocarbons 162ppm, Carbon Dioxide 8.98%, Carbon Monoxide 0.69%, Oxygen 2.11%, Correction CO 1.07%, LAMBDA 1.11

I asked these garages about coil pack or MAF sensor but they disagreed that this could be the problem.

Please can anybody help??????:confused:

Incidentally, the new cat makes a high pitch noise under load which goes when you ease off on the throttle. Definitely no leaks on the exaust.

Wont be a MAF it doesnt have one.

Was it you who asked this question before? We had a similar question about this before and I advised against fitting non genuine cats as they quite often are way to small and just dont work.

How long has the new cat been on? Sometimes they get better once run in. The P codes you have given arent the VAG codes, have you looked up the explanation on rosstech?

sounds very much like a cheap replacement cat, theres loads of them about and I often get cars in with them fitted for diagnostic and emissions tests.

As a mechanic of 10 years I have seen a huge rise in this very same problem due to the amount of cheap aftermarket cats coming in to the UK from china.

I cant guarantee its the cat of course but I would put £20 on it that if you fitted a good condition used cat or a higher quality new cat the problem would be resolved.

Wont be a MAF it doesnt have one.

Was it you who asked this question before? We had a similar question about this before and I advised against fitting non genuine cats as they quite often are way to small and just dont work.

How long has the new cat been on? Sometimes they get better once run in. The P codes you have given arent the VAG codes, have you looked up the explanation on rosstech?

No, I've only just joined Briskoda. I did read the other post but unfortunately I had already fitted this cheap cat.

The P codes given by Skoda are:

16514 P0130 O2 Sensor Circ. Bank1-Sensor1 Malfunction

17549 P1141 Load detection Implausible value

17584 P1176 Correction behind catalyst. B1 Control limit reached Sporadic

16524 P0140 O2 Sensor Circ. Bank1-Sensor2 No activity detected Sporadic

16514 P0130 O2 Sensor Circ. Bank1-Sensor1 Malfunction Sporadic

I looked up these codes on the net and just get same explanation.

The issue I have is that the company who supplied the cat (Online Automotive) say that the Hydrocarbon level of 173ppm (162ppm in second test) is clearly showing that the engine is running far too rich and that the fault is at the engine not the cat. The local garages have just said that the Lambda figure of 1.00 shows the mixture from the engine is fine but not being adjusted by the cat. All I know is the spark plugs look just how they should and that the car runs fine. So who is right???:confused:

we had a car at work the other day, fitted a none gen cat, problem still their, fitted a genuine cat, problem solved

that was on a pug btw

Wont be a MAF it doesnt have one.

Was it you who asked this question before? We had a similar question about this before and I advised against fitting non genuine cats as they quite often are way to small and just dont work.

How long has the new cat been on? Sometimes they get better once run in. The P codes you have given arent the VAG codes, have you looked up the explanation on rosstech?

It's funny, the guy at Online Automotive, who are saying the fault isn't with their cat, even gave me a price to supply me a MAF sensor.

Surely all those faults relate to a faulty lamda sensor rather than a dodgy cat.

Surely all those faults relate to a faulty lamda sensor rather than a dodgy cat.

Thanks, but I've quoted two sets of emissions figures, one before fitting a new pre-cat sensor and another AFTER fitting the new sensor. Still the same.

What is the HC figure actually saying??????

we had a car at work the other day, fitted a none gen cat, problem still their, fitted a genuine cat, problem solved

that was on a pug btw

Thanks, I SO wish I had fitted a genuine one. But I can't get my money back on this one unless it is proven to be faulty or not fit for the purpose intended.

Sorry to convey my ignorance but what is a "pug btw"?

Sorry to convey my ignorance but what is a "pug btw"?

Either a small dog with a beautifully wrinkly, short-muzzled face (like mine), or a Peugeot by the way.

Surely all those faults relate to a faulty lamda sensor rather than a dodgy cat.

I was thinking the same.

However, it's possible that a wonky lambda making the car run rich could kill the cat by making it chow down lots of unburnt fuel.

This is a loooooooooooooooong shot, but I wonder if the Cage Mod might help a bit: http://briskoda.net/maintenance-performance/cage-mod-anyone-tried/58457/

Certainly couldn't hurt.

The first figures show that the Lambda is 1, so mixture is fine and lambda sensors are working correctly. This would indicate that the cat is indeed faulty. However, the CO % is slightly on the high side, even with a faulty cat.

The second set of measurements show Lambda at 1.11, indicating a very weak mixture. Together with a 2% oxygen content, I expect that there is a very small leak in the exhaust somewhere.

The course of action I would take:

Just before a exhaust gas measurement I would keep the car at 5000 revs for a couple of minutes to get the cat very hot. This will increase the efficiency of the cat.

Check for air leaks in the induction system, including EGR and crank case ventilation leaking into inlet as the CO value is slightly high and might well have caused the cat failures.

Clean the throttle body.

This is a case which shows that fault codes are only an indication in which area the fault is rather than a true reflection of faulty parts.