Review on Dorman 674-551 Exhaust Manifold with Built-in Catalytic Converter (Not CARB Compliant), Black by Chris Fisher

The engine is now pleasant and quiet. Rather than attempt to install it myself I paid my local muffler shop to install it along with a Magnaflow rear converter and my old 2003 machine is much quieter and seems to run much smoother now. After pulling out the rear catalytic converter, he illuminated it and almost nothing could be seen. With the new Magnaflow catalyst you could see a lot of light shining through the honeycomb catalyst. Now I don't have to wrap tape around an illuminated Check Engine light on the dash. I'm going to touch up the paint on my car and give it a really good clean and I think I'll leave it at that for a while. Before installation, I also cleaned the casting burrs and bumps on the inner skids, as well as the seal on the manifold that matched the connections with the supplied seal. I did this with a couple of rolls of sandpaper and tumbling rolls and 1 3/8 inch honing balls that I bought from Revain and fine sanded with an 80 grit rotary sanding ball cut to the size of the holes. After the mechanic returned from a test drive, he said it was a fast little car. I think that helped a little as it seems to have better throttle response now. I think I'll drive 1,000,000 miles or more even though he's got a lot of miles.