jspinelli8

My sister has a 2004 civic ex auto and at high speeds (45-65mph) when she tries to accelerate it seems as if the car gas trouble shifting? Im not sure. But it’s as if the car is redlining at 3.5-4k rpm. The car shakes and if you keep on the gas for a few seconds it will eventualy upshift but theres obviously a problem. Im not sure what exactly it is but if anyone could help me out i’d appreciate it

NDNV

What has been the history of ATF maintenance? If you haven't been doing a drain and fill of Honda DW-1 ATF at least every 3rd oil change, then you are behind in this service IMO. You may need to play catch up here with a 3 times drain and fill of Honda DW-1 ATF while driving in between to refresh the ATF. No flushing is advised.
Another area of stumbling or stuttering or hesitation at highway speeds is a failing EGR valve or clogged EGR ports with carbon. Some have described the symptoms of this problem as driving over washboard type roads.

jspinelli8

The trans fluid hasnt been changed in a while.. thanks for the info i’ll try that and see if it woks