Secondary Air Intake Carbon Build-Up Clean-up

HI, BMW 545i, 2005 with 115 k - secondary air intake system codes (P0491, P0492) - air passages have carbon build-up, both banks. Recently started to get codes (P2187 and P2189) - system too lean at idle speed, both banks, engine would die at stop signs or red lights. Dealership wants $6ooo (to remove engine heads and clean-up the build-up), some claim to use Seam Foam Spray cleaner on throttle body plate and later drive for 10 min at 5000 rpm to help to brake the build-up. I want to know opinions - will Sea Foam spray work, have anybody actually get positive results or am I standing before a very costly repair or putting my car on fire?
It is love-and-hate relationship
Thank you in advance, Denis.

You can probably get this job done for $1500 instead of $6000 - consider getting a quote from a really good indy. This engine and it's basic architecture has been around now for a lonnggggg time - lots of people know how to work on it

You can certainly try seafoam, just be extremely slow about injecting a liquid into your intake process. However, if your air passages in the SAI system are truly blocked, seafoam isn't going to do jack for them.

on another thread here... BMWOEM1 said u can remove the sub frame and exhaust manifolds and support the engine,,,, and clean the pasages from underneath... not sure what the cost difference would be. but it sounds better than having to remove the heads... and an easier task.. ive been lucky so far at 91,000 mi. im crossing my fingers it wont happen....

Thank you, guys, will start to look around for a shop and consult with them. Reading info on this forum it seems to me that sea foam solution won't help in my case. It actually very depressing to have a such nice car and be always in and out of shop. Since I've bought it I had transmission replaced (put rebuild ZF), new ABS module, new battery, new water pump, new engine coolant compartment, new alternator and several other things. Fortunately out of $17000 the extended warranty I have paid around $15000 so far. It's been a pain to deal with them - I've paid $4200 for the warranty, NAC pinnacle plan. At this point they refused several things and refusing the current secondary air intake problem.

Will post later how things are progressing.