97 Accord with JDM F23 swap. When I'm on the highway say going 60mph, and I floor it. The rpms will go to like 5 and it will feel like the engine literally isn't going anywhere! This never happened on my old F22. I was always able to floor it on the freeway and gain speed fast, but I can only give like 3/4 throttle on my F23 before it will lose power. Is this actually even a problem or what? I really don't know what to think because It's never happened before.

 

I'm no expert or anything, but you may actually have a clogged catalytic converter. Just a thought. You can mash the gas, but it should feel like it's holding back, like you're not getting anywhere like you used to be able to do.

 

This might actually be the problem. I have had a rattling sound in my exhaust for some time now. Also, when I perform a cold start, my idle sits at like 1500rpm until It warms up, then it drops to 750.

 

Actually it started doing this the day I got my engine swap. Here's a video:

 

Yeah... definitely that rattling noise from the exhaust makes me almost certain that your catalytic converter is indeed clogged! Hopefully it's just a bolt on, then you can do it yourself, no probs. If it's welded on, then you're gonna have to go the more expensive route. Judging by your video, it may be more than just the catalytic converter. I can't help you there... so goodluck!

 

How's fuel pressure?