I have a 94 coupe with a D16Z6 with a Y8 head, DNX 4 into 1 header, and some no name aftermarket exhaust system with no cat. Today when I started it, the engine sounded like a Subaru WRX Sti. I live in Ohio, and it was in the low 30's. Would outside temps have any affect on the engine/exhaust? It also wasn't as loud as it was yesterday and I seem to have a loss in power. Any ideas??