I have used Al-Garcia’s plumbing in my townhouse and for our HOA and they have been good. They are located in Torrance they service our area. The last man that fixed our plumbing valve outside was did a great job. They did work on two of of my toilets and I haven’t had an issue since. You can also try Craig’s Plumbing in Mar Vista. They don’t answer their VM often but they’ve done a good job when they do. 310-204-3133 or 310-398-0194