[st5486]

Hi,

My car recently scraped by the last MOT emissions test and I have a cat 202 error so all the symptoms seem to be pointing to replacing the cat as it has been destroyed somehow....

I've had several garages quote me in the region of £300 to replace the cat alone, and it'll be a bit more for the lamdba sensors. I was hoping to save a bit of money and do the job myself though - I've seen a cat (approved) online for just over £100 and sensors for £40 each so I could save myself a lot of money. Except I don't know how easy it's going to be. Does anyone have any experience with this kind of job? I'm fairly competant and have most of the tools needed at my disposal - I replaced the discs and pads on my car recently and done a few other small bits and bobs like checking the rear shoes and replacing spark plugs etc etc.

I had a look under the car this morning and the cat is attached to the intermediate pipe via a clamp and the other end is attached to the end of the engine manifold via 3 bolts and a gasket.

The problem: The clamp bolt and the other bolts are pretty corroded and I couldn't remove them with my spanner and the manifold nuts are difficult to get to from underneath the car.... Is there anything I can do to make removal of the cat easier? I think adding the new cat will be fairly easy, it's just removing the old one that will be difficult.

 

[madnoel10]

Firstly find out what caused the CAT to be damaged in the first place - no point in spending money on a new one only for it to be ruined.

Do the sensors need replaced - they may be re-usable.

 

[st5486]

I've no idea what could have caused the cat to go bad in the first place? How do I check?

It could have taken a bash before I bought it. The light cam eon about 2 weeks after I bought it so I'm guessing the previous owner knew about the problem but just reset the DTC code. Therefore I have very little knowledge about the history of the car and what condition most of the components are in.

There's nothing noticably wrong with the running of the car. A lot of Clio owners talk about the coil packs and juddering but I have none of those types of problems so I'm at a loss to try and find the cause of the cat going bad.

 

[st5486]

Anyone?

 

[VelSatisfied]

What can cause a cat to fail (without there being anything actually 'wrong' with the car) are bump/push starting or driving through standing water whilst the cat is at normal operating temperature.

Also, (going back a few years now), using leaded petrol, or lead replacement petrol could poison the cat, but that hasn't been available generally for a good number of years - so its unlikely to be the issue with your car.

HTH

Paul

 

[Lagdti]

I'd say the favorite thing to kill a cat is unburnt fuel entering it,and as the 1.4 16 valve Renault engines have a tendency to eat pencil coils I would suspect that this is the cause.It doesn't often happen immediately so a coil may have failed for the previous owner and now you are paying the price for it.

I would be very wary of using cheap cats and universal Lambda sensors,they are often more hassle than they are worth.If you have to replace the sensors then I would at least source some with the correct connections for your car (have a look for NTK sensors in particular).Cheap cats often cause more problems than solve them,expecially if you have a downstream sensor as you car will.They are cheap for a reason......

 

[st5486]

Hmm ok thanks guys. I didn't think there was much to a cat though, right? It's just a ceramic mesh that sits in a box? So how do the cheaper ones differ from the more expensive ones?

Also, the garage up the road has quoted me £220 for a new cat, fitted - what do you reckon about the price? The most expensive cat I've seen on the net (non-sports) is around £150... but when I questioned this the garage said the part price is £220 but they'll fit it for that price as well, which I thought was a bit odd.

 

[madnoel10]

Hmm ok thanks guys. I didn't think there was much to a cat though, right? It's just a ceramic mesh that sits in a box? So how do the cheaper ones differ from the more expensive ones?

Also, the garage up the road has quoted me £220 for a new cat, fitted - what do you reckon about the price? The most expensive cat I've seen on the net (non-sports) is around £150... but when I questioned this the garage said the part price is £220 but they'll fit it for that price as well, which I thought was a bit odd.

Don't forget a decent CAT will contain platinum (and very expensive it is too). There are other metals and chemicals which do a similar job but not as efficently. Hence the masive difference in prices and quality.

Many exhaust fitters do what is known in the trade as free fitting but in effect the labour cost is hidden in the price of the parts. Most of these companies can negotiate a 50% discount from their suppliers.

There's no such thing as a free lunch - Caveat Emptor - Buyer Beware.