My Cat is whining.. need help

[JustPinItFoxxy]

Hey gang, what better than a snowy day to get thinking about sledding!! Except now that I recall.. my Cat was making a winding noise and flashing her check engine light the last few rides last season so I thought Id see if anyone else had similar problems.
Its an 07 M8 and made a winding noise when I'm off the throttle.. it's really noticeable going downhill. The check engine light was also on intermittently. Can anyone suggest possible causes/fixes? Thanks in advance!

 

[slomo]

diamond drive bearings go bad all the time in those had a similar noise and that is what i found

 

[neilsleder]

The whining would be your DD as already said. Butthe check engine light is probably something different.

 

[tavis43]

DD x3

 

[KatMan]

DD x3

Maybe it is actually a cat under the hood

 

[JustPinItFoxxy]

Thanks all.. hoping it's not too expensive?? haha

 

[Slamnek]

DD mine made the same noise but no check engine light. I replaced all the bearings inside with a BDX kit and put a double wide in as well for the main bearing