Exhaust note gets deeper randomly

[Leo71]

Alright guys, I ve noticed recently the exhaust note on my avensis gets deeper now and again, sounds like it's blowing but it isn't according to a mechanic who's had it up on a lift. Anybody experienced this? 

[Konrad C]

I thought I might have experienced this when using more 'throttle' at lowish revs. It was like having a K&N filter. Basically induction roar. 

I have not noticed it since my clutch change, as the air filter box and piping had been removed and put back. I had to remove them again to access a problem, due to the clutch fitter not reconnecting the gear position sensor properly. I also replaced the air filter which was dirty. I noticed that the air inlet pipe to the air filter box should have a foam gasket at the join. I have not done anything about that and the car has not repeated the noise, due to my light foot driving style, and the car seems very lively to the throttle.

Should be a simple fix.    

[Leo71]

Cheers Konrad, I'll have a look at the airbox tomorrow.

It was serviced fairly recently.Maybe things weren't put back quite as good as they should've been.

[Artiom]

I have a similar issue with my Auris - after a service it became "louder" around 1400-2000 rpm. I never thought the air box may cause it...