I will try to make this very short. I have a 99 accord lx 4 doors auto. got the car from an auction with mechanical problems and when I got it I started and it was making a very loud noise from the timing belt. first thought, the engine is bad. replaced the engine, all new belts, water pump, the works. started and the same thing happened until the coin dropped and I realized the cat was clogged. unbolted the 3 14mm on the manifold and the car ran very nice and smooth for a few minutes. after that started to choke every time I step on the gas and the car will die. if I let it sit for a bit and start again and hit the gas the car will run ok in high rpm (around 3.5 – 4) let go of the gas will run good in idle but if I hit the gas again it choke and die. any thoughts? before I get hit in the head here let me list the parts replaced : timing belt, balancer belt, water pump, drive belts, spark plugs, throttle body gasket.as of today the cat is off and the only code i got from the get go was the first o2 sensor, nothing else. so for now the only thing is the car is runing without both sensors.

 

Do you have a timing light?

Did you replace the typical maintenance items, like the distributor cap, distributor rotor, and the spark plugs (only use NGKs recommended in the owner's manual).

 

not the cap and rotor, not really needed and i dont think it is related to the problem. i do have a timing light and the timing is dead 0, o issues there.

 

I asked about the timing light to verify that you are getting adequate spark to the plugs.

The next item I would check is the fuel pressure. Finding the proper adapter will be tricky.

You may also want to pull the vacuum hose from the fuel pressure regulator to see if you get a strong smell of gasoline from a ruptured diaphragm inside.

 

I had the hesitation/power loss on mine, and it was indeed the fuel pressure reg. I built my own fuel gage using a vaccum T and 3 pieces of fuel hose I had in my garage, and a tire air gage, dial type, and hose clamps. I checked fuel pressure, it was low, and I temporarily shut return line - pressure went hi - to test fuel pump. Gage was pretty accurate, after replacing regulator the reading was by the book.