good ol p0300 misfire

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02-27-2022, 03:53 PM

bustymatty

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good ol p0300 misfire

so i’ve been having this p0300 code on my 2003 350z for quite some time now, i’ve gone through the works replacing the coils(z1), plugs(ngk), and injectors(bosch). also gone through and bought new gaskets for the plenum even did a valve cover job because it was leaking oil, it was also leaking a bit into the plugs at least i think i never saw a puddle of oil in the tubes but when i pulled my plugs before doing the valve covers i saw some oil on the threads and o ring of the plugs. i also have freeze frame data of my fuel trims being excessively high, i’m at a loss here guys if any one has any ideas it would be greatly appreciated!
i ended up replacing the valve covers and still a misfire but no leaks!
DTC_CNT : 2
FUELSYS1 :CL
FUELSYS2 : CL
LOAD_PCT :18.0%
ECT (•C) : 98
SHRTFT1 : 6.3
LONGFT1 : 9.4
SHRTFT2 : 2.3
LONGFT2 : 9.4
RPM : 650
VSS : 0
SPARKADV : 16
IAT (•C) : 34
MAF (g/s) : 2.75
TP : 1.2
O2B1S1 (V) : .280
SHRTFTB1S1 : 7.0%
O2B1S2 (V) : .190
O2B2S1 (V) : .090
SHRTFTB2S1 : 3.1%
O2B2S2 (V) : .280
thanks for any help! i know you guys are the Z experts