BMW 4.6 is poor acceleration and hesitation

[upallnight]

Sound like your converter are busted up inside and choking the engine because it can't exhaust the gas fast enough. There was another guy that had the same issue.

Here's the link http://www.xoutpost.com/bmw-sav-foru...der-fixed.html

Before buying new converters, here's a video link on how to test the converters.

https://www.youtube.com/watch?v=9TlygJMxTps

[bcredliner]

Originally Posted by upallnight

Sound like your converter are busted up inside and choking the engine because it can't exhaust the gas fast enough. There was another guy that had the same issue.

Here's the link http://www.xoutpost.com/bmw-sav-foru...der-fixed.html

Before buying new converters, here's a video link on how to test the converters.

https://www.youtube.com/watch?v=9TlygJMxTps

It could be a cat, trace that rattling to the source, they rattle when they get bad

[bcredliner]

Originally Posted by upallnight

Sound like your converter are busted up inside and choking the engine because it can't exhaust the gas fast enough. There was another guy that had the same issue.

Here's the link http://www.xoutpost.com/bmw-sav-foru...der-fixed.html

Before buying new converters, here's a video link on how to test the converters.

https://www.youtube.com/watch?v=9TlygJMxTps

If the exhaust place has the capability to run the test of back pressure (see video in the above) or similar appropriate test, yes, if not, there is a chance you will be buying a new cat that you don't need (I don't think that will be the case but it could).

If you replace the cat and it goes away, one of the two shops you visited that has the capability to run engine tests should test if there is still something going on that caused the cat to fail. Assuming the coils that were replaced were actually bad, the fuel not completely burned could have destroyed the cat.

To be sure it won't happen again, the engine should be checked to see if the root cause has been eliminated.