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Looking at all the parts changed looks like you covered all possibility's that the problem should be fixed .
But this we see quite often and all boils down to a bad catalytic converter .
Remove the up stream O2 sensor and do a exhaust back pressure test .
Is the misfire a hard misfire or just a slight misfire that comes and goes .
Do you have COP (coils on plugs) or HT wires .if wires check the spark on each four if the No. 2 is not strong like the other 3
replace wires .
Please do the back pressure test for a bad cat and get back to me if needed.
For exhaust back pressure test you need a pressure gauge. Its checked at the first O2 sensor which you have to remove .
you should not have more than 1.5psi back pressure anything above is a bad cat .
no need to drill holes just remove the O2 sensor just after the exhaust manifold .
in same cases just removing the O2 sensor and starting the engine you will in some case
feel that the misfire has gone if this is the case remove the cat and replace if its the law in your area.Greg
Disconnet the O2 sensors .
Clear codes and start is misfire still there .
What was the compression reading all the same or one cylinder higher than the other two .
Do you have live data on your scan tool .if yes?
Get me the data at idle for :
Short fuel trim .MAF.
Then again at 2500rpm.
Sounds odd swap the spark plug 1 and 2 .id still code P0302 then spark to #2 is weak
Check that you have a strong spark on #2 as with #3 and 1 .
If compression is good ,spark is good fuel is good then i can only see a problem with the fuel mix to #2.
For live data copy yes as said idle then 2500rpm .
You need to get to operating temp as you are still in open loop .
Is this your idle speed .