hey, so im getting p0300,p0301-302 codes, build motor big turbo etc etc, my hpttuner telling me im getting like anywhere from 2-255 misfires yet car doesn't drive differently, i changed the plugs alrdy still get the code, gonna do a comp test even thou compress should be good did one like 2 weeks ago , and thoughts? tune? coils?

 

Do you have a lightweight flywheel?

 

What cylinders? Maybe try swapping the coils. my lightweigh flywheel dosnt cause any issues on my setup. Could it be the ported head?

 

Grounds good?

 

Spark plug gap in spec?

Edit: I see you changed them so that probably isn't it. Have you taken the valve cover off to check the lifters and all that?

 

gap is .025 and cyclinders 1,2 my spark gap has to be that due to blowout ummm ported head hasnt caused me any issues

 

What brand of plugs?
Are they torqued to the right spec
Check your coils
Clean your maf with special maf cleaner.
What gas are you running on? 91? 93? E85?
Are your injectors seated properly?
How many miles are on your fuel filter?
How olds the gas in the tank from when you did the build?
Check for vaccum leaks.
Do a leak down test?
Check if grounds are tightened down and clean the grounds and the surfaces if you have painted parts the paint has to be buffed off where a ground is connected.
Check your tune maybe you still need to fine tweak some cells in the tune
Who ported the head? Was it machined or done by hand? And if so was each cylinder flow benched and or measured with a barrett?

These are all questions I would look into or things your should Check?

 

Is ur car actually throwing a code or is hp tuners just saying there is misfire with no actual codes thrown? Cause my dashdaq threw false misfire sometimes, and if ur o2 sensor is bad it will happen alot

 

throwing a code