Im telling you man, I can like 99.99999999999999999999999% guarantee that as soon as you get 2 1/4 piping on that car you will see way better times. Because im assuming if it was anything like my CX piping it's about 1 1/4? Trust me changing the piping will get you muchhhhh better times.

When i had my ITR swap done (RIP) i had a spoon 4-2-1 header w/ 2 1/4 collector flanged to my stock 1 1/4 CX piping w/ stock muffler with maby a 2'' tip. I had all my interior in my car and 1 person; drove it, then got piping done had 3 people in my car at about 200 pounds each with no back seats and it was 2x as faster then with 1 person in it. When i had the stock piping i also fell out of VTEC by 2-300 rpms then it would crossover. I got the piping done and i stayed in it the whole time shifting at 85-8600 rpm's.

Also I had no cat or res. on it . Get exhaust and get back to us cause now im anxious to see what happens. good luck and I hope that it's the problem