Hello,

I have a 03 G35 Automatic . Recently installed a new engine (mine threw 3 pistons lol). I got everything put together took a bit for it to get started and once it did it reved up all cylinders firing then when it comes down to an idle the car starts misfiring than stalls

I got 2 Codes
- Knock Sensor
- CAN COMM

Im replacing the knock sensor tmrw but if that doesn’t work i’m at a lost. I’ve checked fueling , spark and air and nothing seems off. All grounds are connected. Just need some help w this!

(Also there’s a bit of a leak at the headers to my test pipes could that cause a stall on idle?)

 

I'd start checking all grounds, vacuum lines and gaskets (intake, t-body), PCV system and perform ECM reset. I'm not sure if your engine also requires throttle body relearn like my 07 does..
Minor exhaust leak won't affect engine performance like that..

 

Ya i’ve sadly done all that, going more into it once the car gets warm (from me starting all the time) it decides to work fine doesn’t stall and idles fine but if it’s cold it’ll just die.

Ive had two codes pop up for
(P0011) Bank 1: Camshaft Position Timing over Performance
(P0021) Bank 2: Camshaft Position Timing Over Performance

​​​​​​​Not to sure at this point

 

Check this Reddit post: P0011