hesitation/lope while driving
 

I'm new to this website but am hoping someone can help. I have an '03 Accord EX that has started to act up. Once the car warms up it seems to have a hesitation/loss of power momentarily. It only last for a moment but you can definitely feel a lack of power. It happens both at low speeds and higher speeds. Also, when in Park and I rev the engine, the tach goes up and then shows a drop of RPM's, but it recovers and then continues to rise. No warning lights come on and the SEL does not come on either. Car has a newer battery and brand new alternator and Serpentine belt. Any ideas? Thanks for any help offered.

How many miles are on the car? What maintenance items have been changed?

I would still stop by a parts store and have them scan for codes just to be sure there is nothing saved on the PCM. Post any codes on here with the code actual number. Codes start with the letter P and have four numbers, like P1234.

It's got just over 85,000 on it with normal maintenance done. The guy at the store wouldn't hook it up since the SEL wasn't on. I have a guy at work who is going to bring in his reader tomorrow and I'll see what codes pop up if any.

I would look at the maintenance items like replacing the air filter. Check your owner's manual for the time/mileage interval to replace the spark plugs. I think they are due every 110K miles, unless some other type of spark plug was installed.

Is your car a 4 or 6 cylinder?

When you get the hesitation when the car reaches operating temperature, does the hesitation only happen once, or does it keep happening after the car is warmed up?

Air filter only has about 3000 miles on it. The hesitation happens more than once, it is pretty frequent. Wasn't sure if it was the O2 sensor or possibly the EGR???

I think that you will have to do some more diagnostics. I wouldn't blindly replace an O2 sensor, unless you are getting a code for it. Or the scanner is showing that your sensor is not showing the proper readings.

I don't know how the EGR passage is set up on your car. Once again, it should set a code if the EGR is giving you problems.

If you can test for fuel pressure, that is also another item that you would want to test when the problem pops up. That would involve routing a pressure gauge, so you can see it while driving.

I would avoid the temptation of throwing parts at the car. Doing maintenance items like cleaning the EGR valve or ports is a good idea. Also, inspect the spark plugs for any cracks in the porcelain, or wearing of the electrode, etc...