The injectors were Nismo 615s that had about 30,000 miles on them. I was trying to track down a fuel pressure problem and while it turned out all of the injectors were in good shape they had picked up a variation of a few percent across the range, presumably from crud build up over about two years. I can't find the results sheet at the moment but it was 3-4% and that was back down to less than 1% after cleaning. So probably not an essential service but certainly not a bad idea to send them off every few years. And witchhunter is certainly a good place to send them. Fortunate for me they're local and I was able to drop them off and pick them up the next day, completely with full results sheet, new caps and new o-rings which was a nice. Definitely a big recommendation on their service.
