I've instaled MAPEI grout on my bathroom tiles, falowed all instructions, used little water to clean up and still got grout haze. I have salfamic acid to cean up and intructions say to wait 10 days after cleaning. Its been 3 days since I've grouted, what would happen if I use the acid before the 10 days.

What type of tile or stone do you have?

The grout needs time to cure before any strong chemicals are used. The cleaner could deteriorate the grout surface if done before the recommended time.

Have you tried to buff the tile with a white bristle type pad yet?

Need to know the answer to the first question before you try the next step.
I would try a 50/50 mix of white vinegar and water first before you use any strong acid type cleaners.

Yep ... 50/50 white vinegar and warm water will work most of the time.

I have glased porcelain tile on the floor and ceranic tile in the shower and tub suround.

Your ok to try the vinegar/water first.

ok thanks, I will try that first.