cat

flea72

about 4m ago, was driving along, and the engine management light came on, within a few mins, the car started to misfire, went into limp mode, and then stopped and wouldnt restart

got recovered to local dealer, resulting in new plugs and coil pack. was warned misfire could have damaged cat, but highly unlikely

Now the engine management light has come back on, so took car to dealer. the only fault code they get is for an ageing cat. replacement has been quoted at just under £500, however they say until i start to get actual problems (other than warning light on), then its up to me, whether i want to replace it just yet. They cleared the codes, the light went out, and stayed out for about a week, before coming back on again

they have said, there might be an underlying fault that is causing the cat to fail, or it could just be due to the previous breakdown. but until i pay for extra investigative work, they wont be able to say (just plugging in the examiner cost me £50 this time). they did say they cant just replace the cat, as if there is something wrong, then the fault will kill the new one too

so, my main question is, is it ok to keep driving the car, with an 'ageing cat', or if i continue to drive it, will it cause other problems?

F

KonkyWonky

How old is the car and is it on its original cat? How many miles has it done?

Cat failures are fairly uncommon, generally if the cat is faulty there is an underlying reason ie faulty valves, unless it is an old cat that has come to the end of its life.

There may be a possibility it is just the lambda sensor that needs replacing which is a simple fix but if you have already been at a garage I would have thought that would be the first port of call.

As far as causing damage, driving with a faulty cat is unlikely to cause serious damage to the engine. Thats not to say that your engine is not already damaged though and thats whats causing the faulty cat, personally I would be wanting to get it sorted as if there is already an underlying problem it is only going to get worse over time. Your car will also fail an MOT if it has a faulty cat as the emissions will be through the ceiling.

Hintza

We have had a warning light on the car for almost 2 years now. No one knows what the code is and as you say they charge £40-£50 a time to plug it into their machine. I paid for it once got a freebie once and have left it ever since.

The warning light goes out everynow and again but generally speaking is pretty constant (it also says engine failure).

I do howeverr listen to the engine very closely and we don't plan on selling the car so it isn't a huge issue.

However if your car is young and you plan to sell at some stage you are probably going to have to shell out to have it repaired or wait until exhaust dies.

PS I am a bit gung ho at times

andygb

If the cat is damaged and breaks up, then it can/will ruin the rest of the exhaust system. It will be fairly obvious if the cat is on the way out, because you will hear the loose fragments shaking around, and you will possibly suffer power loss. If the exhaust is blocked by loose fragments, then the car could overheat, because it will have to work much harder, and hills will be a nightmare.
I would say get it fixed ASAP. I had mine replaced a few months ago (9 year old Mondeo, 98K miles), and the difference is remarkable.

flea72

KonkyWonky wrote: »

How old is the car and is it on its original cat? How many miles has it done

the car is 7yrs old, and has done about 55k

it is on its original cat, has been serviced to schedule, and last year it had a new exhaust fitted

andygb wrote: »

If the cat is damaged and breaks up, then it can/will ruin the rest of the exhaust system. It will be fairly obvious if the cat is on the way out, because you will hear the loose fragments shaking around, and you will possibly suffer power loss

we do occasionally suffer slight power loss, but this only tends to be when the car is cold, and its very infrequent, and is more common when the a/c is also being used

i wouldnt say i could hear a recurrent rattling around of something, again occasionally, you might hear something, but its not that regular, that you could say, yes, its definitely coming from a certain area of the car - more one day its in the passenger footwell, another day you might hear something in the central area of the car, etc.

although thinking about it, we have been to several garages over the past year, as the exhaust sometimes vibrates, however, they usually find a clip is loose, and retightening it, makes the noise go away, for a while

F