I've got an 04 WRX with 83k miles. It has downpipe,SPT exhaust and flashed to stage2. It's had these mods for almost two years. Now it's burning oil and smoking like crazy. It's not consuming any oil and it's not losing power. At first I thought the turbo seals were going out (good reason to go bigger), but it has not lost boost and power delivery is the same.