Mrsosoo

Sup fellas, lately I've been experiencing some random rattling not to mention power loss and the smell of some fumes. My CEL is on and CATALYTIC CONVERTER, DRIVE MODERATLY TO REDUCE ENGINE LOAD has popped up in my iDrive. I haven't gotten to my mechanic yet but I suspect the catalytic coverter needs to be replaced. Has anyone done this yet? If so what have you paid and lastly, where is the cheapest place to get partts from. Dealer said $1300 for one and $800 for the other. I didn't even know I needed two. Also if you changed your CAT, did you also replace the O2 sensors?

sachal007

you shouldnt have to replace your cat unless you car was running too rich or lean. If you can get under the car and see if the cat housing looks burned, you might have fried your cat. OEM cats are very expensive. Knowing you have a 545i, you might end up replacing both, so thats almost over a $1600 in parts only.

As for sensors, yes you do, coz i think they are the initial reason for your cats going out.

Mrsosoo

Thanks for the heads up

2008550idavid

I had a simliar problem on a 745 and the first mechanic referenced the converters.. I we referred to a dedicated BMW shop and they determined it was the cam sensors causing the issue. Replace both , drove out for a whole lot less money and never had to replace the converters . Sold the car at 217,000 miles ..still strong.

Mrsosoo

@ 2008550... Thats good news to hear, I've been looking around the internet just trying to see what other peoples experiences have been. The price of the parts alone is what is the most scary, I really hope it's something else.

west

The 545 catalytic converters are integrated into the exhaust manifold:



They take some effort to replace because the front subframe will be lowered and the engine suspended.

Mrsosoo

thanks for the feedback, gonna head o the mechanic today

Mrsosoo

So what I thought was the catalytic converter was actually the MAF sensor... glad it was the latter.

2008550idavid

Sweet........Glad the fix was not as expensive as you had thought.