Burnt Lemon

I have 2003 MDX
Having Transmission problem now. sometimes It runs like brand new. lots of power but from last few days it slips, if I stop and apply the breaks it free up the gears,goes to neutral. car doesn't move. I have to shut off the engine take the key out start it again then it moves. while driving it slips again if I repeat the procedure it takes the gears again.

Skirmich

Most MDXs from 01 to 04 have known and well documented Transmission Issues all over the Internet.
The transmission has a design flaw that starves 3rd gear clutch packs from ATF and make it burn faster, When the clutch packs release enough debris it will clog the shifting solenoids all over the transmission which will lead to and/or: Not engaging Drive, Slipping 1st, Slipping 2nd, Sudden Downshifts to 2nd gear at 60mph (This caused deaths as wheels will lock up), etc.
Even if the transmission gets rebuild the Design Flaw will not get fixed which will lead to failing in a matter of years (In my experience around 4 or 5 years).

Summary: Fix it, Sell it, Move On.