Engine misfire HELP!!

[Jwood1410]

2016 base gt started showing random cylinder misfires . So I’ve changed plugs once ,changed coils twice .upgraded to gt350 intake manifold with new 47 ib injectors , New throttle body. I’ve reset the ecu following YouTube instructions . Before I changed all this it would throw the code pretty often now it only does it after driving around an hour . I’ve also went to 93 octane with octane booster . It’s seems to run better but I’m at a loss on where to look next any advice would be appreciated

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[larr12]

Any codes?

 

[Jwood1410]

2016 base gt started showing random cylinder misfires . So I’ve changed plugs once ,changed coils twice .upgraded to gt350 intake manifold with new 47 ib injectors , New throttle body. I’ve reset the ecu following YouTube instructions . Before I changed all this it would throw the code pretty often now it only does it after driving around an hour . I’ve also went to 93 octane with octane booster . It’s seems to run better but I’m at a loss on where to look next any advice would be appreciated

P0305 po306

 

[luca1290]

These are for cyl 5 and 6.
Did a compressione test? If you worked around the transmission or major engine work, have you done a crank relearn?

 

[Jwood1410]

No how do I do a crank relearn

 

[SSG 5.0]

Probably yt have crank realarm. It been 3 yrs ago I did mine so I can’t remember how I did it. Also, it might be a stupid question, the plugs are properly gapped?

 

[NGOT8R]

No how do I do a crank relearn

Most handheld tuners will have this option. I used my nGauge when I did mine.

 

[Jwood1410]

Ok I’ll try that this evening after work

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