When I was entering the freeway on 2nd gear, I hit 5k going to 5.5k. Then the car engine started struggling. Not in a bogging sort of way, more like the engine for weaker and was tryna pull a heavy load. I've checked for codes and everything is fine. One of my friends say it might be the solenoid that needs cleaning or the timing is off. Also, before I bought the car, the distributor had to be replaced. So I'm thinking it could be that too. Anybody have any input on what could be the problem?

...oh the engine is a 94 GSR in a 93 Civic Si....