Roscol

Oem is a one piece pipe which incorporates the quick coolant warmup heat transfer system with the muffler. I’m sure a good shop could cut off the offending muffler and replace, otherwise the OEM pipe is like $4,000.

MattRX

I was wondering what that piece was, thanks for the Info. Agreed any good shop can definitely save that important part and keep it intact while putting in a new muffler. Pipe size is 2.25” on my 350, wouldn’t be surprised if RX450h is the same but worth checking still.

RX in NC

Good luck and keep us posted on how you decide to fix this issue.

carsilike

I took my car to an exhaust shop that said there's no leak. The muffler has a drain hole which is what is leaking water. But I do notice that the exhaust has quite a rumble to it which I'm told it shouldn't. Wondering what else it could be

MattRX

You should send us a sound clip. The RX450hs at the dealership always sounded louder than normal RX350s to me. I’m not sure why but they have a more rumbly and droney note to them. Not sure if that’s the byproduct of the 2GR-FXE or what.

Next place to check would be the donut gasket between the catalytic converter and the other flanges. Also on a cold morning on startup, you’ll be able to see the leak if there is one.

Clutchless

carsilike - how long have you had this RX? It may be you just have to get used to its particular sounds. Especially since the exhaust shop advised your exhaust system did not have any issues that needed repair.
That happens with many newly purchased vehicles.
FYI it may also be that you are hearing the droning noise that many have complained about and the remedy is discussed in this link. It involves installing another damper or 2 on the system to make it quieter. It is a simple and inexpensive modification and is fully discussed in these links, the repair is shown in the second link. I did it to my RX.
https://www.clublexus.com/forums/rx-3rd-gen-2010-2015/694115-the-annoying-droning-engine-sound.html
​​​​​​https://www.clublexus.com/forums/rx-3rd-gen-2010-2015/886847-2010-rx-engine-drone.html

ColAngus

x2 for it's either the drone, or "get used to your new car" scenarios.

NJLEXES

Had same issue on our 2011 RX350 with loud exhaust. It was the donut gasket as you mention

carsilike

Only a few weeks and I believe you are right. I am already getting used to the noises it makes so I will let it be for now