Engine low power?

My car will not rev past 3500 rpm. Im not sure wat it can be ive been told that it might be an o2 sensor, my powertrain control module but I have not figured it out. Please help.

I have poor accelration after tiing belt was relplaced, I hit the gas. Pede; the rpm is 2000 then te speed just hot up from 0, what seems to be the problem?Help"

Ok thanks for the reply, I also have problem, with fluctuating temp gauge, change the thermostat clean the radiator fan is working well, but still temp is fluctuating after long hours of driving, temp starts to fluctuate when on idle or on a stop light then when it accelerates it goes down and sometines go on its normal level below half, then goes vise versa, what seems to be the problem?I already put antifreeze but still it goes the same thing.

Ok il try to ask the mechanic about it regarding the radiator issue, if the head gasket is change it will never fkuctuates?Im afraid maybe it will be the same after I changed the gasket, actualy the history goes like this I purchase the car a month ago while I was driving after a week I notice the temp is fluctuating like I mentioned before, so I went to a machanic and they that they need to clean the rad so they cleaned and it overhaul it, so they did it and it was the same, so I went to another mechanic and he said need to open the head, head was open sent so machine shop for repahsing, openned it up but he put the same gasket, after that place a new thermostat, check the water pump, it was fine, fan is working place new plugs, put some antifreeze, and everything is the same as before, no check engine light on it, I went back to mechanic and he told me need to replace New head gasket, do you think that is the culprit?Pls help I want to be sure that everything is done properly cause some things that need to replace a little bit expensive. Thank you

I have the car listed above EX model, four door sedan.

The check engine light is on, the immobilizer light is flashing, there is no communication with the scan tool. The tachometer is inoperative, the temperature gauge is inoperative. The car runs sluggishly, no acceleration, engine cuts out (bogs down) at higher rpm's greater than 3,400 (when tachomdeter was working).

DLC test:
With the key on or off and ECM's p31 unplugged from the ECM, and measuring voltage from dlc pin 5 (logic ground for ECM) to chassis ground, I get a nine volt reading. With ECM's p31 plugged into the ECM, (key on or off) and measuring voltage from dlc pin 5 to ground, the reading is zero volts. Why does this happen? Is this normal? How does the logic ground function in relationship to the ECM?

Ok will do that thank you

I am stuck having to fix this problem myself because neither the Honda dealership and two other shops were unable to fix this. Definitely appears to be some kind of wire (electrical) problem.

I did find the TPS voltage at the ECM would not measure any higher than 1.7 volts. I get five volts at the TPS plug, and was able to measure 6k ohms of resistance on the TPS. I was also able to vary the throttle valve and notice the resistance vary on the TPS. I realize the TPS can still be non-linear and still be causing problems. I am having with this car.

Thanks for the accurate wire diagram, I could easily follow out the wires, their color etc. Found the bad ground and got is fixed the car runs great! I love this site.

To put it simple the ECM (or engine control module) is in limp mode. Get a new or used ECM and ignition with key coded and save time and trouble. Dealers will charge a substantial amount for this work and programming so check with some auto parts stores or eBay. Make sure the ECM and key ring ignition are paired. If you go through auto parts store write down VIN number, mileage and part number on the ECM. Hope this helps.

Was this issue ever resolved? My car is having the exact same issue. I t is a 2002 Honda Civic two fdoor vetch. It starts runs sluggish especially upon acceleration. The green immobilizer light flashes all the time and the rpm, and temperature gauge's do not work. What do I do?

I am having the same problem with my 2005 Honda Civic 1.7 To a T! Car will not scan and those gauges do not work and flashing key light. Did anyone figure this out? Help!