Catalytic converter & Emmissions?

Lizzyste

Does anybody know what the signs of a faulty catalytic converter are? My car has just failed its MOT but the garage have advised me to get an emmissions test before they carry out any work.
Unfortunately as the back box has gone on the exhaust, I have spoke to someone who could test the emissions but said I would need exhaust fixing first, I dont want to spend over £100 getting exhaust fitted and then the emissions tested if the catalytic converter has gone is there any signs I can watch out for that would indicate that it has gone. I really cant afford to spend too much and I am considering whether to scrap the car. Any advice would be much appreciated.

forgotmyname

A leaking exhaust wont give accurate readings.

Without knowing what car it is and how old then its hard to advise anything. Petrol/Diesel.

What did it actually fail on? You can get a diagnostics check but will cost the best part of
half the exhaust box price and still leave you none the wiser.

Get a 2nd hand box and fit that?

Lizzyste

The car is Seat Ibiza 1999 reg and its petrol engine

Car failed on a couple of things mainly the rear wheel bearings the rear exhaust.

If I were to get the exhaust replaced, would a garage check any of the emissions to see if the exhaust was working correctly?

I dont see point of spending £40 to have emissions tested if its not going to give a proper reading anyway.

rodenal

I don't understand why you/the garage think it needs an emissions test? Is the cat rattling / showing signs of being blocked? If not then just try and find a used back box and have somebody put it on for you. Should be no shortage of them for a late 90's ibiza and is easy work for any exhaust fitter. £50 all in I reckon

mcjordi

any mot garage would check the emissions for you.. my local one did for me when i was trying to resolve my emissions on my old fiesta.. offered the tester " a drink" wouldnt take it said its no bother to stick a probe up the exhaust...

rodenal

The test results won't be right with a hole in the backbox though

MX5huggy

Just get some exhaust repair tape or putty to fill the holes and take back to MOT place to confirm CAT not broken.

Then its up to you whether you fix it properly or stick with the chewing gum!

PS even duct tape might be enough to prove that its not the CAT.

Lizzyste

mcjordi wrote: »

any mot garage would check the emissions for you.. my local one did for me when i was trying to resolve my emissions on my old fiesta.. offered the tester " a drink" wouldnt take it said its no bother to stick a probe up the exhaust...

The MOT garage has checked emissions that why its failed with the exhaust but the guy in garage said need full emission test which they did not have machine for as he thought it could be catalytic converter as well he said if thats case its not worth fixing car.

Lizzyste

rodenal wrote: »

I don't understand why you/the garage think it needs an emissions test? Is the cat rattling / showing signs of being blocked? If not then just try and find a used back box and have somebody put it on for you. Should be no shortage of them for a late 90's ibiza and is easy work for any exhaust fitter. £50 all in I reckon

I dont understand why the garage has told me to get emissions test independently, its failed on emissions because of exhaust on MOT but their machine doesnt do full test he said. What are the signs of it being blocked? thats what I was trying to find out. Exhaust is noisy and noticed a knocking noise now and again.

atrixblue.-MFR-.

to be honest, if your cat was faulty youd know it, a blocked cat will give you next to no power at all, a faulty cat will give you a horrible eggy fart smell like its got gastrousinterritous and poor fuel econemy and may sound like its hollow when you accelerate.

is there any engine check light on?.

what i would suggest, is get you local factor and if money is tight as a nuns ....... then ask them how much for a cheapy make back box. if you hear a rattle now and then and it when you go over bumps its quite possible a rubber exhaust mount are old and now soft and not holding the exhaust rigid.

i would then put some fuel treatment in, to clean up the injectors. when was the last time you had it serviced? low on oil can cause higher emissions coupled with a dirty air filter and caked up spark plugs.

if your car shows none of the signs above then quite possibly a lambda sensor is on its way out have these been replaced in the past? when, lambda sensors are genrally good for about 60k miles, the thiey can go to pot. you dont have to buy OE replacement sensors if they are faulty if you have correct wiring a universal one can cost you only £35.00 there abouts.

mikey72

From what you have said it sounds like it's either not been emission tested because of the exhaust having too many leaks, or it's simply failed the test, and the examiner suspects the cat may faulty.
He can't say for sure though.
He then can't say if the emissions will be ok after you have repaired the exhaust, and is saying it may pass, or he may suspect the cat has gone, in which case it may still fail.
It only has to pass the test the MOT'er gives it, it doesn't need to pass a "full" test, but he can't tell you what to do either, it needs the exhaust fixing first to make a diagnosis.