Having this issue with my wifes SRX. It starts fine when cold but when you drive it and stop for 15-45 min it has a long hard start but always starts. It has 60 psi on the fuel rail and holds after cutting off so its got fuel to the injectors. I have changed the Evap purge valve solenoid, changed all plugs, changed a bad 02 sensor, and checked all coils. Also have tried checking for vacuum leaks but no luck with that either. I get the same p0300 random misfire code and both p0420 p0430 catalytic conv. Please if anyone has any other tricks let me know.