Hello, welcome to the forum.
I have found A chute for you, don't know which company you wanna get it from, but the cheapest one i found was on Walmart's website:
And there is also a chute i found on the genuine MTD website, but its more expensive:
Buy the Discharge Chute Deflector online and get your OEM parts quick! Orders over $45 qualify for Free Shipping.
www.mtdparts.com
Also found a mulching kit, and a pair of mulching blades, assuming you don't have a pair of blades already:
Blades:
These Genuine Factory Parts Xtreme blades are for extreme mulching and bagging performance. They're engineered to outlast standard blades in sandy conditions, and bag up to 50% more grass compared to standard side-discharge blades. Genuine Factory blades are designed and rigorously tested to...
www.homedepot.com
Mulching kit:
This mulching system is designed to turn your ordinary grass clippings into finely ground mulch. The high lift baffle design combined with the included mulch plug will cut and re-cut grass clippings into
www.homedepot.com