MG ZT 180 Auto CAT and Exhaust

[cldcp00]

I am getting a P0420 code on my MG ZT 180 Auto indicating there may be a problem with the CAT. The car has had a full service and I have replaced both VIS motors that where faulty. The car also just passed it MOT today.

Would a bad CAT cause fuel economy issues? The back box is rusting on the outside badly so will need to be replaced anyway

I don't want to buy an OEM Exhaust as this is way too expensive.

Can somebody recommend where I can a good quality aftermarket Exhaust and CAT

Regards

Desmond

[trikey]

Has it ever had a cat fitted? Some aftermarket cats can throw up this code.

[dave lincs]

Code p0420 is the cat not working properly and will throw up this code as the rear lambda is not getting the reading it needs from the cat

this often happens if it has had and aftermarket cat fitted

[cldcp00]

Yes an aftermarket CAT was fitted when I bought the car 4 years ago.

Will this affect fuel economy?

[timspencer]

It wont help....

I would try and locate a good used or new genuine cat and see if that helps, I would replace the rear box and midsection too although aftermarket would be ok to fit.

[cldcp00]

Any companies you would recommend and companies to stay clear off

[dave lincs]

I would try and find a good used one have a word with Trikey as he is breaking a 2004 zt 190 that also has a stainless steel exhaust from the cat back and also the cat is good