I beleive that when you do a full import (full=y) this will override the indexes=n parameter with indexes=y. One way to overcome this would be to do a full export and bring in the tables a schema at a time. You could then specify indexes=n
Writing a shell script to import the tables 1 by 1 wouldn't be that bad. You just have to output the tables and paste them into a file- then paste in the appropriate imp command that excludes the indexes. This should be too much of an effort.
has some reverse engineering scripts that will spit out the table names for 1 or all users.
Can you check what kind of indexes created when you specify
Because when import utility will create system generated indexes such as LOB index, OID index and unique constraint index (include primary key) regardless of the setting of INDEXES parameter. Set INDEXES=N only disable the creation of user generated indexes.
I think this is the reason you got different result when you use different setting.