sql server - Sql Select Query Timeout -

hello guys working on query , every thing working fine except when run query more 2-3 times return timeout there wrong in query or server error kindly suggest me here query

select        category_feature_mapping.feature_id,     category_feature_mapping.category_id,      option_table.option_id,       option_table.title,      feature_table.title featuretitle,      feature_table.type      category_feature_mapping      inner join feature_table          on category_feature_mapping.feature_id = feature_table.feature_id     inner join option_table          on feature_table.feature_id = option_table.feature_id       category_feature_mapping.category_id = @catid     , feature_table.feature_id=@feid     , feature_table.feature_id not in (select                                              feature_id                                                                                        vendor_value_table                                                                                        vendor_id=@venid)                        group     category_feature_mapping.feature_id,     category_feature_mapping.category_id,      option_table.option_id,      option_table.title,      feature_table.title,     feature_table.type 

try append ";connection timeout=100" connectionstring timeout