Last month I bought a 2017 JCW 2-door, 61,000 miles, clean carfax that showed regular service at their Mini Dealership. Two days after I buy it the check engine light comes on. I have a Mini code reader and saw one fault for catalytic converter. Dealer picks up the car at my house to take it back to the dealership to check it out. It was bought at a GMC, Buick dealership. Long story that I will not go into but here is what I am asking and what they have found.

Could this messed up mod by the previous owner caused engine damage that I will find out miles later down the road? Could there be engine damage and still runs fantastic?

Today find the previous owner installed a high performance "something", that is my word, in front of the stock catalytic converter. It was covered by the stock pan so they could not see it at first when they were checking the stock converter based on the code, weeks ago. It was still showing that fault. Today they are installing a new stock catalytic converter, taking out the mod that was installed prior, to make it all stock at my request. During the installation they find the O2 sensor had been cross threaded and not a sealed connection. They are installing a new O2 switch tomorrow and the new converter.

My question is, has that set up caused engine damage that I don't know about or is it leading to engine problems down the road. The rest of the mechanicals all check out. This dealership sent it to the Mini Dealer in Indianapolis to check it out a few weeks ago before they returned the car to fix. Don't ask me why they just didn't have the Mini dealer do the repair, that is the million dollar question, since they ordered the parts from that same Mini Dealer.

I will probably get the car back sometime tomorrow or Saturday.

I am not a mechanic but I love driving Mini's. Have I bought "a problem" ???

 

The F56 platform is dead reliable outside the upper motor mount issue and front control arm bushings.

I hope for your sake they're installing a genuine OEM MINI converter.

 

Sounds like the previous owner installed a cat less downpipe. Supposed to be a performance mod but I doubt it added much and it won’t pass smog that way. I am all for performance enhancements but not at the expense of deleting smog equipment. Anyway it should not do any damage. It just lets the engine breathe better. Since they put it back to stock with a brand new cat your all set. Enjoy the new ride!

 

Yes, all parts installed are OEM Mini parts, purchased at a Mini Dealer. I was told the converter was a $2,000 job. On their dime.

 

Thank you for this information. That is great to know, much relief.

 

The Cat converter on the exhaust "mid-pipe" is actually the secondary, the primary cat points down from the turbo outlet. Some here replace that with a "downpipe" Its technically a straight pipe.

Im surprised the dealer missed that, but you did say it was a Buick dealer, so its understandable.

Confirming others, that downpipes would not cause any damage to the engine.

One thing you dont know, is, did the previous owner have a "flash" tune" done to compensate for the hatless downpipe.

 

If it was purchased at an auction, they probably own the bill.
If it was traded in there, legal litigation can be sought under threat of Federal prosecution against the PO.

 

It was purchased at an auction.

 

that is the concern I have. If they didn't have a "flash tune" am I looking at engine trouble down the road? You would think if someone went to the trouble of doing the mod for better performance they would also tune the engine to their new setup for maximum improvement. Will never know.