The previous owner purchased them from CZP due to the warranty back in 2009 and probably only put 10K miles or less on them (the Z has only 75K original miles)...guess I need to start saving up for some Nismo injectors...and might as well get a higher cc and upgrade the chip again. Wonder if these injectors are the cause of my hard starts when the engine is hot....probably not.. but I guess possible....thanks for the help and input!