Postby VStar650CL » Sun Dec 12, 2021 8:26 am
The P0325 is a knock code and it's common for it to persist on older Nissans even when the knocks are brand new. It won't light the MIL and I wouldn't worry about it. If you have the top off the engine at some point, just replace the knocks while you're in there. Or you can relocate, that works fine.
The P0140 may be a result of your IVT issues, so I'd go after that last. The VQ35's are Miller-cycle engines and IVT codes will prevent the ECM from running the cam phasers for Miller-cycling. That can in turn fool the ECM into thinking there's a problem with a cat or sensor. So resolve the P1135/P1140 first, then worry about the O2 sensor code if it persists.
The P1135 is usually a "sludge code" while the P1140 usually indicates a bad sensor, so your oil change may well have cured the former. Check your passenger side cam sensor for crud or magnetic debris, and try swapping the driver/passenger sensors. If the P1140 (right) turns into a P1145 (left), the sensor is bad.