What causes hesitation in a 2007 honda accord v6

All the above are great ideas , one more, check electrical connections on throttle body and spark plugs. Clean with small wire brush or knife to scrape contacts to remove corrosion. Time is the cost / either way ,but with labor rates between $70.00 to $110.00 per hour plus un-need parts U can save $$$$$$$$$$$$$$.

It would help to narrow down the actual "hesitation" your speaking of. There could be a hesitation in the transmission. This would be known as slipping and usually there's not a quick fix for that. As far as engine hesitation, there a are several key areas to begin. First, fuel, does the car stutter like its running out, clogged fuel filter (not as common as one may think in an 07 car)could be the culprit, fuel pump may be getting weak or even dirty injectors. SEA FOAM is a great additive and I use it for several uses. Other things to look at would be a bad coil(s), this would cause a misfire, greatly reducing performance, although that should cause a check eng light, even if intermittent. Spark plugs, have you ever replaced? Excessively worn plugs will run ok until under a load, like acceleration. A little more info may help pin this down for you, and run by a local parts store,Advance, AutoZone, etc, they have a free diagnostic service and even w/o a MIL on there may be codes stored in the ECU. Good luck and hope this helps.

All the things RUSTFARMER has said are correct but i would also advise using a fuel addative in the first instance , get one that covers the catalytic convertor as well as the fuel injectors, valves etc , this will remove any carbon etc build up on any sensors etc , give the car a longish drive (50 miles) or so at a highish speed to get engine to a good working temperature and take it from there , also you hav'nt mentioned if the OBD codes have been read , this will need to be done as well to help pinpoint the fault

Could be many things. I assume no codes are set, so bad TPS possible, bad cat converter or muffler, even coolant temp sensor or O2 sensor starting to fail. Tune up items also.