i have been battling to fix this misfire and would appreciate any help, tips, thoughts on what could be causing. it started right after my TLS/RL Camshafts install

it usually happens during cold start up

what has been replaced from this List:

Common Problems That Trigger the P0300
Worn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable)
replaced 6x Spark Plugs NGK and 6x Ignition coils (used). do we have a distributor cap?

Incorrect ignition timing
i could not recreate the problem when i took it back to my Camshaft installer so hopefully it isn't this

Vacuum leak(s)
any thoughts from where if any??

Low or weak fuel pressure
any thoughts/suggestions?

Improperly functioning EGR system
swapped for a brand new Genuine Honda EGR for $300.00 - still misfiring

Defective Mass Air Flow Sensor
swapped out today at Acura since i have upgraded 3.7 TB and Manifold from MDX 2010. $50.00 brand new genuine Honda/Acrua part

Defective Crankshaft and/or Camshaft Sensor
i went to a junkyard and found the location of both our Sensors for V6 to be on the left side? if so, its behind the timing belt possibly?


Defective Throttle Position Sensor
i replaced this recently

Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems
it doesn't feel like any of these. Accord still runs great, just HATE seeing Check Engine Light blinking and/or coming on


Common Misdiagnoses
Fuel Injectors - picked up a used set plus rails but install is pretty extensive and would rather do Transmission Cooler install before this
Oxygen Sensor(s) - i believe there are four, 2 upstream and 2 downstream. one may need replacing due to sitting on my PCD and becoming melted a bit. maybe this is the cause of CEL?
also, i had an Exhaust leak from the Flex Pipe on my Tsudo J Pipe so that Flex Pipe was properly fixed for $200 since welding is beyond me


Powertrain/Drivetrain problems

Thanks for any help, suggestions, advice

at this point, i am at a dead end...

 

What year vehicle?

Regardless, the cause can be due to the valve clearances, especially on the exhaust valves.

 

LoL damn son, the money you spent tossing parts at this thing,you coulda just paid a shop with proper skills and equipment to check it.

Im with Tech8, it sounds like a classic case of improper valve lash.....