FWIW the O2 sensors will not last forever. It may not be a bad idea to replace them in the near future. They are easy to get to.
174,000+ miles, 5/20/12 new ej257 short block, 8/20/11 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. Also CHECK YOUR OIL, these cars use it.