Is this an accurate assumption?
 

I performed a valve lash adjustment not too long ago. Put all the gaps to factory spec. What use to be a beast like 2002 Accord coupe 5spd turned damn gutless! It still idled fine and sounded fine but just felt like i had the a/c cranking. Initially all the intake valves were loose and I couldn't even fit the feeler gauges into the exhaust they were so tight. Now comes the assumption... I have a big ol cold air intake system and DC 4-2-1 headers with a cat back exhaust. Would any of those things require a tweak to the factory valve lash? Any correlation between the two? I'll thank anyone in advance

engine mods versus valve lash spec
 

I performed a valve lash adjustment not too long ago. Put all the gaps to factory spec. What use to be a beast like 2002 Accord coupe 5spd turned damn gutless! It still idled fine and sounded fine but just felt like i had the a/c cranking. Initially all the intake valves were loose and I couldn't even fit the feeler gauges into the exhaust they were so tight. Now comes the assumption... I have a big ol cold air intake system and DC 4-2-1 headers with a cat back exhaust. Would any of those things require a tweak to the factory valve lash? Any correlation between the two? I'll thank anyone in advance

Set them to factory spec's using the proper procedure.

I've merged your other thead into this one.

Thanks. Noob mistake didn't see the general tech section. So is my car slower now because I did the valve job incorrectly? Its not noisy or shaky just slower. Could it be a possible timing issue?

And it doesn't seem to go any slower when I do turn the a/c on. Before there was a definite performance loss with it on. The only other thing I did was tighten the power steering belt because it was vibrating. Would a tight belt cause a power surge? Its not terribly tight

I was actually hoping for a bit of a different response then the whole "did you read the instructions first" type deal. I thank you for not referring me to the search bar however. So Kudos on that

Just a thought, did you reset the ECU after you did the valve adjustment?

Only other thing I could think of trying would be a leak down / compression test.

When was the last time you did an ignition inspection, plugs, wires cap and rotor?

Not sure if any of this applies, but just some questions...

- Cam timing shifted a tooth when engine was being turned during valve adjustment? Easy to verify by checking cam-timing marks.

- Valve adjustment with engine cold?

- Valve clearance measure at camshaft vs. measured at valve? Not sure which is correct, but it does make a difference. Verify, but I think Honda traditionally measures at cam lobe for DOHC & valve stem for SOHC engines.

I used the dipstick in the cylinder head for top dead center. And the can markings lined up too. I put the feeler gauge below the adjuster screw and above the valve stem. I recently took the rotor cap off and inspected the inside and all looked good. No pooled oil or signs of excessive wear. Wires fine and only two spark plugs had slight blackening. Other two looked clean. It seemed before VTEC would engage at a low rpm and now it doesn't do anything until redline... if at all