Code P1065 & low acceleration symptom
I'm looking for any ideas as to what the issue could be here, it's been ongoing for a few months now. I have a 2004 350z w/ 150k miles. Only mods are a K&N cold air intake, and Invidia Gemini catback.
It started right after I had a shop install a new battery, and coincidentally just 2 days later I was driving normally and out of the blue the engine got way louder and my acceleration was basically gone. It sounded like a bad exhaust leak. I drove it around a couple miles and no codes ever came on.
Had another shop look at it for me, they did some data logging and said it kept pulling timing & that the VVT wasn't doing anything. Long story short, all they did was replace the spark plugs & knock sensor/harness before I gave up on them and took my car back home to look at myself.
Test drove it a couple more times, finally got some codes: P0011 'A' Camshaft Position - Timing Over-Advanced or System Performance (Bank 1) and P0021 'A' Camshaft Position - Timing Over-Advanced or System Performance (Bank 2). Oil pressure was fine, idle was fine, startup was fine, revving it at idle was fine, literally the only symptom was when you really get on the throttle above 2-3kRPM, there was just no power behind it but a lot of noise, similar sounding to an exhaust leak or a misfire (shop was 100% confident it was not a misfire). Some people suggest looking at the MAF because I suppose it was possible that I over-oiled the K&N filter, but the MAF is only two years old and the sensor looked perfectly fine and free of debris, sprayed it with cleaner anywhere and reinstalled but that didn't do anything. Also looked at the VVT solenoids, the screens were perfectly clean and clear of debris, no gunk whatsoever (religious oil changes since I got the car).
Decided to check for exhaust leaks. Disconnected the catback from the cats, lo and behold the passenger side CAT failed, basically the honeycomb material was still intact but it completely shifted sideways and was blocking most of the airway. I thought I found the problem, so I ordered Berk hi-flow cats as well as Tomei headers, and I also bought an ACT clutch while I was at it. Installation went fine, booted the car back up, again sounded perfectly normal at idle and when revving. Took it for a test drive, same exact power loss symptom still, only without the loud noise because the cat blockage is now gone.
Now i'm getting code P1065 ECM POWER SUPPLY which has never showed up before. I don't know what to do at this point. Clearing the code did nothing. I tried an ECU reset before installing the cats/headers but that did nothing. Any suggestions?