Will big shared_pool_size adversely impact the database performance?

My environment is oracle version 10.2.0.3 on solaris 10.

We had the ora-04031 error before that is because our shared_pool_size is too small to handle the system. We have  increased since. My question is shared_pool_size the bigger the better? Will a large shared_pool_size negatively impact the database performance? Right now, the system is running slow. Of course, there might be other reasons such as outdated statistics.

Our memory setting as follows:

open_cursors = 2000

db_files = 1000

shared_pool_size = 860000000

db_cache_size = 60000000

java_pool_size = 150000000

streams_pool_size = 60000000

large_pool_size = 9000000

pga_aggregate_target = 30000000

session_max_open_files = 20