Hey everyone,

About a year ago, I snagged a manual 2003 Nissan 350Z, but it came with three bad coil packs. I swapped them all out for new ones, along with fresh spark plugs, to fix a misfire issue caused by faulty valve cover o-rings. Replacing those rings, covers, gaskets, and adding a new PCV valve did the trick.

However, lately, I've been dealing with intermittent stalling and a misfire again. I tried cleaning all six spark plugs and checked each coil pack individually, noticing changes in idle when unplugged. (I've yet to resistance test them but they're <1 year old, I suspect it could also be a dead ignition coil due to the P0350 code)

I also threw in a new crankshaft position sensor and did an ECU idle re-learn, which seemed to help a bit (The car developed a really lumpy idle and then would struggle to start prior to doing this). I've got camshaft position sensors lying around, but I haven't installed them yet. Oddly, no check engine light is on.

But the misfire persists, and the car often stalls when the revs drop. I ran an ECU scan and pulled these codes:

- P1615 - Status 3 (Difference of key)
- P1212 - Status 1t (TCS/CIRC)
- P1614 - Status 1t (CHAIN OF IMMU-KEY)
- P0350 - Status 1t (IGN SIGNAL-PRIMARY)
- U1001 - Status 1t (CAN COMM CIRCUIT)
- U1000 - Status PAST (CAN COMM CIRCUIT) [IPDM E/R]

Any ideas or suggestions on how to tackle this issue would be much appreciated.

Cheers,