I have a 2000 Accord ex with the f23a1 motor. It has 165000 miles on it. I have had the car for a little over 5 years. I have done all the maintenance on it. Two years ago I changed the timing belt, distributor,cap and rotor,wire plugs and few sensors. I have not had any problems with it until the past 6 months probably. When I am in fifth gear and just coasting not giving it any gas when I go to start giving it gas to accelerate it will blow out a large cloud of smoke out the exhaust. It doesn't it especially bad if I'm going down hill. Now it's starting to get worse any gear your in if your not giving it gas as it's slowing down sometimes it will backfire and then smoke when you start giving it gas. Then when you clutch it to come to a light the rpms drop clear to almost nothing and about stalls. Now if you go from a dead stop and climb though the gears it runs fine no smoke or sputtering and if you go down a hill and put it in neutral you can rev it and no smoke put it in fifth and start to give it gas again and no smoke. If your in like third gear and letting it coast then start to give it gas and it smokes if you push the gas pedal harder it almost sounds like it's flooding it's self. It doesn't smoke on start up you can rev it and no smoke. It seems to be burning oil some but not going though coolant or anything. I ran a compression test and all 4 was pretty good right around 180. I've changed the pcv valve and put a oil catch can on it which it does collect a small amount of oil like maybe enough to fill a shot glas every couple weeks or so. Any thoughts would be appreciated thank you.

 

Possibly worn valve seals or guides if the smoke is hazy blue.
This would account for no start up smoke and only smoke under engine braking.
No oil up in the head at startup but when decelerating the oil is sucked in by the vacuum from the closed throttle pulling through the seals/guides.

Pull the plugs and inspect them.

 

Thanks for the reply the plugs are dry not oil soaked or anything. I can't tell if it has a blue haze or anything.