2007 Lexus GX470 Engine problems

I own this lexus 2007 gx470, at 120,00 miles has a completely overhauled and now 143,000 miles all yellow warning lights illuminated that including "engine" the engine starts make noise and king of dragging somthing, after diagnostics. "The secondary air injection system switching valve stuck open both one and two" I called dealer and total parts cost me $1,200 not include labor yet. That's ridiculous.

I am the owner of a 2006 lexus gx470 (vin [[redacted]]). A month or so ago, at or about 56,500 miles, the check engine light came on along with about three other yellow warning lights. Also, the engine went into a mode that barely allowed me to drive down the road. On or about january 27 of this year, I limped to the lexus dealer for inspection. As the attached report indicates, my vehicle was diagnosed with a failure of the secondary air system with a repair estimate of $2,114.60. (See page 9 of the attached...