Hello All,

I am UK based and I am pretty sure my catalytic convertor is on it's last legs, there is an awful rattling sound coming from the car.

Upon raising the car, there is a section of the exhaust that looks like a resonator or muffler of some sort toward the middle of the car, that I believe is the rear cat (I could be wrong) and that is where the noise is coming from. It sounds like whatever is inside it has broken apart and is rattling around inside causing the noise. I have no performance issues, although there is a juddering at idle speed which is getting worse with time.

Having looked for a replacement cat on the net, I can see the section that is rattling seems to be part of the N/S cat.

I just have a few questions that I am hoping the community can help me with:

1) Is this part thats rattling actually the catalytic convertor, I don't see an 02 sensor (Lambda) in it?

2) Can this section be removed and replaced with a straight through pipe?

3) Do I need to replace both the O/S and N/S cats?

4) Where can I get a reasonably priced replacement cat in the UK? I've seen them for about £200 on eBay for the N/S - is that about right?

I apologise for not having taken any pictures of the troubled part of the exhaust, but I know the cat can be a common fault our cars and am hoping someone might know what I'm talking about and be able to help.

As always any help or guidance will be greatly appreciated.

Regards

AR

 

Think I've got the same problem - did you get anywhere with yours?

 

If it is one of the rear cats, it can be removed and replaced, at your peril with the MOT, with straight pipes. These cats are not monitored by an O2 sensor, but they do scrub the exhaust that last little bit to make it as clean as possible.

If the MOT knows it's supposed to be there, it might cause them to fail you. If they don't know about it, these engines run so clean that the exhaust sniffer should see a clean enough gas stream to pass you.

 

I think I'll try the breakers

 

Remember that these cats have a scrap value because of the precious metal in them, platinum, 3 to 7 grams in each.
Collect the beads, put them on a string and give them to your wife, don't tell her where you got them.

 

Correct again! A repair shop would be happy to "dispose" of them for only a small fee...

 

O2 sensors are usually upstream closer to the engine so if it's the back CAT, it likely won't have anything attached. You could put a straight pipe or clean our the CAT substrate and reinstall the shell (if it's even possible to get out the substrate. HOWEVER, I'd suggest getting a new one -- possibly aftermarket or you might be able to find a used one from a scrapped vehicle as well. I'm not sure what they cost in the UK but you should be able to get one somewhere in $300 US Range.

See if Converterwarehouse.com might carry one or discountconverter.com or use a universal application like this:
Magnaflow 99105HM Universal Catalytic Converter (Non CARB compliant) | Frugal Mechanic

Good luck.

 

Try these links:



Catalytic Converter | Cheap Catalytic Converters - Cats2U.co.uk


CHRYSLER CROSSFIRE 3.2 11/03 on Catalytic Converter OS