Currently have a 97 Civic DX. Stock D16 engine 111xxxmiles N.A. with
DC sport headers, MSD ignition with blaster coils, AEM Dry Flow air intake, AEM TRUTime Camshaft adjuster and a GReddy TurboXS exhaust system with no catalytic converter. The car is still slow and im not sure why.
The diameter of the muffler is around 4inches and very noisy. Ive been told that bigger is better but others say that its too large and I should switch it out. Not really sure what else to do but any feedback will help.

Just trying to make it faster but not sure what else to do. Also trying to keep it natural because of the mileage, not so sure a turbo will make it last.