I brought my 2001 LS430 with 200k miles on it into the shop I have been going to for years (not an authorized Lexus mechanic) with a check engine light and VSC system light on. They error code was P0307, which indicated the 7th cylinder is misfiring. The shop recommended replacing all 8 ignition coils and spark plugs ($1,650). The cost of the coils is the largest component of the cost (labor was only $250). I asked them why replace all 8 coils if the code says only 1 is misfiring. The response I was given is that they have seen this many times before and if 1 coil goes bad, they will all