ISR High-Flow Catalytic Converters for G37/Q50 - 200 Cell Metallic Core | VQ37VHR Test Pipe Alternative | Street Legal Power | Deep Aggressive Tone | Direct Bolt-On for 2008-2013 G37 & 2014-2015 Q50 3.7L RWD

Unlock the real potential of your 2008-2013 Infiniti G37 Coupe/Sedan or 2014-2015 Infiniti Q50 3.7L RWD with ISR Performance High-Flow Catalytic Converters engineered to replace the heavily restrictive 600+ cell factory cats with 200 cell metallic-core HFCs that slash backpressure, increase exhaust velocity, and unleash horsepower while still keeping emissions equipment for states that require it, because the ISR HFCs use a 3" inlet/outlet design with a high-temp 200 cell metallic substrate that flows 300%+ more than stock while still scrubbing exhaust gases to reduce smell and keep you street legal where test pipes won’t pass, delivering a proven 10-14whp and 9-12wtq with instant throttle response, harder mid-range punch, and screaming top-end pull to 7500 RPM that test pipes provide but without the raw fuel smell or constant CEL headaches, and the sound transformation is massive with a deeper, more aggressive VQ tone at idle and cold start that builds into a loud, raspy, exotic wail at wide-open throttle that makes your G37 or Q50 sound like a tuned JDM car, while the metallic core and proper sizing eliminate the tinny, hollow rasp that cheap test pipes are known for, and each HFC is built from heavy-gauge T304 stainless steel with full TIG-welded seams, CNC-machined 3" flanges, integrated O2 sensor bungs with anti-foulers, and a brushed finish that resists corrosion, cracking, and heat failure through track days and daily driving, and fitment is 100% direct bolt-on for VQ37VHR G37 and Q50 3.7L RWD using all OEM mounting points with zero cutting or welding, tucking perfectly with factory heat shields and clearing the steering rack, subframe, and chassis braces on manual and automatic cars with no rattling or interference, and the kit ships complete with multi-layer steel gaskets, Grade 10.9 hardware, and extended O2 sensor defoulers to minimize CEL issues on most stock tunes, and they pair perfectly with ISR, Z1, Motordyne, or any 3" cat-back exhaust to build a full high-flow VQ37 system that sounds insane and makes real power, so if your G37 or Q50 3.7L feels choked, sounds stock, and you want test-pipe power without the smell, rasp, or legal risk, ISR High-Flow Cats are the best streetable upgrade to boost VQ37VHR performance and sound, and every set is jig-welded, pressure-tested, and QC inspected for flange flatness, core alignment, and weld penetration so you get ISR’s proven fit, flow, and reliability without the cracking, leaks, or CEL nightmares you get from cheap eBay HFCs.