HKS Hi-Power Cat Back Exhaust Honda Civic SI Coupe 2017-2021 | 31006-BH001

I’m prolly more mature than most Si owners so I look for function as well as form. This exhaust has changed the personality of my 19 Si! It feels more like a 2.0 than 1.5. The change is especially obvious in the mid range and top end, from speed limit to triple digits is so quick now. Yes, it gets boomy at around 3,000 rpm and it’s a little louder than I’d hope for, but it is just awesome. Never thought I’d b this happy. I have vast experience with Honda and Acura and I know generally speaking, aftermarket parts usually only end up diminishing ultimate performance, as these cars are designed and engineered so well. The “straight thru” exhaust is free flowing and opens up the lungs of this little sweet heart; works great with stage 1 tune!

Great exhaust. I have another from HKS on my S14. The quality is what I've come to expect from HKS. The note is perfect, not too loud, not farty, raspy, or boomy,

I've read some less than perfect reviews on here which made me a little nervous about my purchase. However, my exhaust came in a timely manner and everything was in perfect condition. The HKS was exactly what I was looking for; still a good daily volume but definitely noticeable when I get on it.

I put this on the day I received it. Sounds great and looks nice. I'm glad this is the exhaust I went with for my SI.

I originally wanted the HKS for my SI but It was not available and then this was a second recommendation in place of that. It has an amazing growl to it and it looks sweeeet !