The only thing I can think of that you may have problems with is that the power steering pump can sometimes leak on to the altenator which sits below it. If the power steering pump is leaking, it's best to replace the power steering pump and the altenator at the same time to save shop labor costs as it's guaranteed the altenator will go out soon after. I've seen this repair cost close to $700.

Other than that, the earlier LS400s are known to have their guage lights burn out and the LCD screen on the radio to fade out. I'm not positive on the cost to fix the guage lights, but they do need to pull the whole cluster. For the radio LCD, you will most likely need to probably need to replace the radio unit depending on the year.