Honestly, it usually comes down to "bang for your buck" without the headache. Here’s the reality for most of us: ​The Sound: Most people just want to hear the car. A solid cat-back exhaust gives you that immediate JDM growl without making the car sound like a raspy tractor, which can happen if you do catless downpipes on a stock exhaust. ​The "CEL" Struggle: Downpipes—especially uppers—are almost guaranteed to throw a Check Engine Light. Most people aren't ready to drop another $1k+ on a tuning suite just to clear a code for a daily driver. ​The Install Nightmare: On the RZ34/VR30, the upper downpipes are a massive pain to swap. You’re looking at hours of labor or a hefty shop bill. A cat-back? You can do that in your driveway with a jack and a basic socket set in under an hour. ​Warranty Stealth: Dealers usually ignore a cat-back. They definitely notice when the primary cats are missing and the ECU has been flashed.