I have a 2001 Honda Civic EX. It runs Perfect most of the time. But sometimes is just starts running on half power. The rpm's drop and if you press the pedal the rpm's don't go up as they should. The cars maximum speed is 20-30 mph. I don't know what the problem is. Can anyone help?

 

If the engine doesn't run past 4,000 RPM's, the car is in "Limp" mode. Do you have a Check Engine Light showing?

 

That happened to my 93 celica. Ended up being bad spark plug wires, the metal prongs actually came off the wires for the spark plugs. Check that first, could also be fuel pump i think. But i should probable throw some codes.

 

Try resetting the ECU. Remove fuse #6 (15amp) from the fuse box under the hood. Wait about 30 seconds before reinstalling it.

If the car goes into limp mode again, or your MIL (check engine light) comes on, have the car scanned and post the codes here. Many auto parts stores will scan it for free.




These cars don't have spark plug wires.

 

catalytic converter could be clogged....

 

So you say most of the time? so it is safe to assume that its just a Temp problem?
I would try as was stated reseting the ECU, I would also pull all the plugs and look to make sure they are fresh... 1 other thing is that you can look at your clips going to the coil packs.... start the car and gentley move the wires a little and see it if start or stops the problem...
1 ?.... Is the engine lite on?