Rep Power: 0

I have a 98 Honda civic with 86k on it. When I first start driving it it is very peppy and drives nice, as I keep driving it the acceleration gets worse and worse. It also feels like it skips sometimes when its accelerating but only between 2000-4000 rpm after that range it accelerates smoothly but still not as fast as normal. I have checked the CAT and it was not clogged, I have replaced the upstream O2 sensor. Replaced the ignition coil, igniter, cap, rotor, plugs and wires all with Honda brand parts. The engine idles very smoothly and sounds pretty good overall. These problems only started happening after I replaced the ECU because the last one was shorting out on me. It has also been getting really hot lately so the issue may be heat related since it gets worse the longer I drive it but If I let it cool off its peppy again. My last ECU was causing my car to sputter and sending the engine revs up and down erratically before stalling out, could that have damaged my engine? Any help is appreciated.

 
Rep Power: 235

I suspect a bad headgasket. The reasoning is it only does it when warm. Any coolant loss, milky oil, mis-fires? Do a compression check. Is it throwing any codes?

 
Rep Power: 0

I checked the coolant and it's at the right amount. The oil is not milky at all. I finally got it to throw a code though and I brought it to the dealership since they have been doing other work on it. They said it was a "vtec code". They didn't give me any exact details or look into it though because I brought it in right before they were closing.

 
Rep Power: 0

I'am having the same kind of problems with my 01 civic ex 1.7 liter v-tec.This started when i changed the alternater when it gets warm gauges act funny battery light is on,rpm drop the srs and alarm light are on than car stalls.The dealer thought it was the computer control module we put a used on same problem.I think i'll take it to another honda dealer.

 
Rep Power: 0

West Calif your problem might also be wiring if it's not the ECU. I would have the dealer take a close look at all your wiring to make sure it is intact and not shorting out.

 
Rep Power: 0

That's what i think its a electrical problem,thanks for the info jf

 
Rep Power: 0

I figured my problem out! I don't know why I was so dumb but all these problems didn't start until after I replaced my ecu because my last one was breaking. I did the old take off negative battery cable to reset computer trick and now she's driving like a champ again.