BMW 4.6 is poor acceleration and hesitation

[Aman]

Originally Posted by sethhatfield

I had a rattle but the material was so crammed in there by the end it stopped and was plugging up the exhaust. Yours is probably moving around in there still which is why it gets better occasionally. Mine is a 4.4 but I doubt the cats are different. My engine has 130,000 so we're not far apart.

I knew the coils wasn't it because I swapped them and the misfire stayed put. I also swapped plugs around.

I'm afraid it will come back after the crap in them blocks the exhaust again.

Thanks for your help.
Suspecting the cats is seeming more likely now
Is there any chance you could have a look at the video of the sound I posted on page 2 and let me know what you think?
Many many thanks

[sethhatfield]

Originally Posted by Aman

Thanks for your help.
Suspecting the cats is seeming more likely now
Is there any chance you could have a look at the video of the sound I posted on page 2 and let me know what you think?
Many many thanks

Yes that is the material "honeycomb rock" inside the steel can shells banging around in there I'll bet.

Worst case, you change the cats a year too soon because they are going to need replacing anyway.

[Aman]

Originally Posted by sethhatfield

Yes that is the material "honeycomb rock" inside the steel can shells banging around in there I'll bet.

Worst case, you change the cats a year too soon because they are going to need replacing anyway.

Hi just wanted to check, did you ever find something wrong with the engine that caused the cats to fail, or did they just fail without anything from the engine causing them to fail?
Thanks

[sethhatfield]

Originally Posted by Aman

Hi just wanted to check, did you ever find something wrong with the engine that caused the cats to fail, or did they just fail without anything from the engine causing them to fail?
Thanks

No just time and mileage.

[Aman]

Just out of interest, is each tail pipe for a separate bank or do they join together?
It's just that I notice more noise and steam out of the right one, the left tail pipe has a lot less steam and noise

[bcredliner]

Originally Posted by Aman

Thanks for your help.
Suspecting the cats is seeming more likely now
Is there any chance you could have a look at the video of the sound I posted on page 2 and let me know what you think?
Many many thanks