I have the codes on the hesitation problem...Help please!

Brothers,

Codes 300, 301, 303. Engine Cylinder Misfire.

2000 Civic Si, 36k, AEM short ram for the past year, otherwise stock. 30k
service performed last October.

Car hesitates in the midrange RPM band after the warm at around town speeds.
The worst was yesterday when it would not climb past 3500 rpm in 3rd climbing a
small hill, which is when the CEL activated. Fuel tank is 3/4 full.

So far I have:

Tightened the gas cap
Removed and cleaned the K&N and the throttle intake with intake cleaner
Replaced the fuel filter
Visually checked for loose vacuum hoses or anything else that seems wrong under
the hood.

After I did the above (based on the engine not getting enough fuel or air), I
reset the computer and the CEL is gone. However on the test drive (In which I
ran through redline to 100 mph) the car afterward still displayed the
hesitation problem at low speeds.

What the hell is the problem? Could it possibly be a bad tank of gas?

Please, help me out...It's driving me nuts.


Steve -- The Bluesman

"I fear no Evil because I walk with Evil..."

 

could be faulty fuel injectors, spark plugs, an open or short in harness
between fuel injector and ECM/PCM or crankshaft speed fluctuation sensor.
Cylinder 4 is not misfiring so that's a start.