My wife's Ford Fiesta had a new catalyst fitted.

Arnold Clark offered me a Ford part or a third party part (Autopart) and I chose the latter due to price.

After 1 week an engine management light appeared and the garage diagnosed this was due to a non Ford part being fitted.

I now have a going round in circles conversation with Arnold Clark where they now recommend  the Ford part after just recomending a third party part.

They would again  recommend the third party part but it might not work again. Why recommend the part again if it might not work?

Any help/solutions would be appreciated. 

Don't waste time arguing with Arnold Clark. If they didn't put a disclaimer on the original repair using none Ford parts it is there problem to sort it out now.

Contact Ford 'Customer Relations Department' and register a complaint.

Customer Relations Department
Number One
1 Tony Wilson Place
Manchester
M15 4FN

Telephone : 0345 712 5490

email : [email protected]

Firstly, I don't disagree with Unofix's suggestion.

but I'm curious....

If it's a 2017 car, I'm surprised it needed a new catalytic converter.

How did you (or AC) know that it needed a new one?

AC's explanation seems to suggest that EVERYONE who fits an Autopart catalyst will have this problem - I'd be surprised at that too.

Could it be a faulty sensor? If so, there's a different conversation to be had with AC (or perhaps Ford).

I'm with @alanfp on this. I very much doubt that a 2017 car would in most cases need a new catalytic converter. I strongly suspect a misdiagnosis and they are trying to cover there backs.

They get you to pay for a full price genuine Ford catalytic converter, and while it's in they change a sensor and give the car back and say "see it was a poor quality part, and you needed a genuine Ford part"