My friend overheated his 2002 Honda Accord ex 2.3L vtec. there was oil in the coolant but no coolant in the oil. we broke it all down and sent the head to the machine shop. the machine shop told us that the head was way too clean it had to have been taken off before because it was too clean for 100,000 miles. we put it all back togather replacing all gaskets and head bolts and torquing everthing to specs. now it runs but it runs like crap if you try to rev the engine it wants to die and will die if you let it. the check engine light came on once and it was the idle air control valve, i took it off cleaned it out and now no check engine light but it still runs like crap

 

Check all vacuum lines; PCV, brake booster, etc to make sure they are correctly connected, not damaged or leaking.

Check your intake manifold for leaks by spraying carb cleaner around seams. Any change in idle speed suggests a leak.

Check your fuel rail/injector and injecto/manifold connections carefully for leaks.

If you have a timing light check for flashes (spark) on all leads when engine is running rough. No flash means no spark is being delivered to plug; bad distributor cap, rotor, wires, plugs, coil, ignitor.

What codes were shown earlier?

good luck