As title says very loud rumble and vibration upon start up and continues to 3500rpm through all gears. Car does need o2 sensor after cat. Exhaust doesn't look like it's vibrating at least not bad enough to create the sound. Also the sound and vibration is heard inside cabin not out of car

 

Post a video with sound.

 

Did you use aftermarket mounts? If so that is likely the cause.

 

I just picked the car up the swap was done already I'll post a vid and some pics after work. In pretty sure the mounts are not stock though

 

Sounds like you may have bought a car with solid mounts. You will get a lot of vibrations and noise in the cabin with solid mounts.


IMO, get used to it and welcome to Hondas.

 

OP could also re-install the stock mounts to eliminate the rumbling, assuming that the mounts are the problem as seems likely.

 

More likely the OP will have someone showing him how to change them, but yes that is the best solution for him. Unless he likes the solid mounts. I hate mine, but I like how the car drives with them.

 

I can change my own mounts. I just wanted an idea of some places to look as I haven't had anytime to thoroughly go over the car. I will still post pics

 

Well if you can change your own mounts I think that would've been the first thing to look at.