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A few days ago me and the Mrs had a nice run out, top down to a nice little seaside town called Grau du Roi on the edge of the Camargue. Most of the way there & back we were just tootling, but at one stage I had to engage warp drive to get past a member of the 35mph club who had been holding me up for ages. As we blasted past Reginald Mari du taupe the induction noise suddenly increased to an alarming level. I thought it was the cone air filter arrangement that had come adrift, but as the car was running OK and we were not in any real hurry we kept on going. As we neared home, we had to climb up a hill off the Alès ring road and in doing so it was obvious that not only was the car making a lot of noise, but there was no power. Despite that, we managed to get home without incident and I left the car to cool down before doing any investigations.

A quick look into the engine compartment from the boot grille showed that the air intake assembly was still in place, but after I'd run the car up onto the ramps and had a quick look underneath it became evident where the problem lay - shaking the exhaust showed there to be a rattle, localised in the cat. Seems the cheapo after market replacement I bought a few years ago was the source of the problem - the ceramic must have broken up and was partially blocking the exhaust.

The price of an OEM replacement from the usual UK suspects was bloody expensive, over £300 by the time you pay the VAT and carriage, so I decided to look elsewhere. I finally bought one from Germany, type approved, carrying the correct E marks and guaranteed, with a fitting kit. All in and delivered for 88€. Whilst I'm tempted to try and fit it myself, I have a problem these days with vertigo and crawling underneath sets it off. I will take the car to our local garage and ask them to fit it. They're usually very reasonable. They've recently replaced the front flexible section so they've had at least half of it apart already. The duff cat was changed about 6 years ago and the car doesn't do much mileage so the bolts haven't rusted up. They've had a good soak with plus-gas just to be on the safe side.

Moral? Caveat Emptor when you buy cheap. Fingers crossed that the new replacement will be of better quality - it certainly looks it, but that's Germany for you. Emisssions were marginal last MOT so hopefully will be OK this next time.

Happy F ing.

Reckless Rat wrote:Seems the cheapo after market replacement I bought a few years ago was the source of the problem - the ceramic must have broken up and was partially blocking the exhaust.

It's a fine balance, if you only do a few miles a year and the cheap cat lasts several years it's not bad value, it's when it fails within a year it is a problem.

However 88€ for a quality cat is a bargain.

Changing Cat after 6 years is good value for money, so I would not be overly fuss about that. Ceramic inside cat is going to brake and can make you problems.
You can go my route, and buy stainless steal custom made exhaust with metal instead of ceramic inside the cat. But then you will have louder noise inside the cabin, which you will have to bear with.

Not sure how much of an issue the CAT age is - the exhaust system on my 04 TF160 was original when I got it at over 65k miles. I changed the back box as I thought it should have failed the MOT with that much corrosion and the strap failing, and all was definitely original as the nuts were terminally set. Going through more proper MOT at our very trustworthy local garage they described emissions as near perfect with CO almost unreadable. Might be changing CAT before long as casing is starting to look not long for this world.
Mike Satur/Piper back box, might go for his manifold too

Just got the car back from the garage - I had them fit it because crawling underneath these days just sets my vertigo off. They showed me the old unit - all that was left inside was a great big block of ceramic ratting about like a skeleton in a dustbin. Car now runs as sweet as a nut. Hopefully all will be well in February when it goes for its contrôle technique.

Just as an aside - the car has done 115,000 miles, it is 20 yrs old and it still has the original silencer. I guess living in a mediterranean climate and not getting wet very often (if ever) does have its advantages.

For info - the company I bought the Cat from is called ATP-Autoteile. I bought it via their Ebay.fr site and they deliver europe wide. (take time to shop around because prices differ from country to country). The Cat bears the proper E markings.

Link here: http://www.ebay.fr/itm/KATALYSATOR-KAT- ... 2749.l2649

Post Mortem.

This is the Cat which has just been removed. Outwardly it looks fine - there's no corrosion, just a little heat burnishing. I can't remember when it was fitted, but I guess it was probably about 6 yrs ago.



However, when you look inside you can see why it's nothing but a pile of scrap. The ceramic honeycomb has separated and broken up, finally lodging itself at 90° to the flow of exhaust gases, hence the lack of power and response. I presume the rest has been shot out of the tailpipes.



I might just save the casing in case I decide to do some track days with the car.

You lost the ceramic mat that keeps all catalyst in place and after that the honeycomb just rattled around until it broke up. The cost of the catalyst has little effect on the ceramic substrate as all catalyst manufacturers buy in the substrate from substrate manufacturers ( Last time I looked there were only two companies specialysing in the substrate - the equipment investment is horrendous )- It looks as though in your case the catalyst supplier had economised on the mat.

TP

Roverlike wrote:Changing Cat after 6 years is good value for money, so I would not be overly fuss about that. Ceramic inside cat is going to brake and can make you problems.
You can go my route, and buy stainless steal custom made exhaust with metal instead of ceramic inside the cat. But then you will have louder noise inside the cabin, which you will have to bear with.

Roverlike wrote:Changing Cat after 6 years is good value for money, so I would not be overly fuss about that. Ceramic inside cat is going to brake and can make you problems.
You can go my route, and buy stainless steal custom made exhaust with metal instead of ceramic inside the cat. But then you will have louder noise inside the cabin, which you will have to bear with.

Metal catalyst will stay put but won't necessarily get you through the MOT, the alumia coating used to give you the surface area for the catalyst sticks better to ceramic than stainless steel ( expansion and thermal shock ). We used to supply Metallic catalyst for production series racing. The car would pass emmisions at the start, but what little precious metal and alumia remained after the race would not have stood a hope in H.being straight stainless steel at the end. The racing teams liked metallic because they stayed put avoiding ceramic breakup - but they had to be replaced after every race, it really was amazing what a v12 at racing temperatures could do.

TP