Originally Posted by kmh_RED
well i added a high flow cat and exhaust to my civic 4dr and it improved it really good, you can tell the difference on how fast it gose now but thats what i can tell from it my parts are from ebay tho... cause im on a really low budget
Probably more psychosomatic that anything else. When I added exhaust, it felt faster too, but only because it made more noise.