Interesting, I don't have any codes and also just recently passed inspection. However, emissions for me may just be checking for codes instead of measuring output.I've been thinking of future performance upgrades and one was a high flow catted downpipe. F 150 and musrang forums seem to think the SPD is quieter than the CVF but that the SPD will throw codes even though they both use essentially the same cat. I don't know what to believe but I already have the Magnaflow because it was the least noisy 'performance' exhaust. If you're saying the SPD is loud it really is a discouragement.
I have the GFB DV+ and run it with the spring. I feel it makes the on and off turbo response a little more refined. Less lunge in response to getting back on the gas in mixed driving.
Cool, now we have an extra reference. It seems noisier than what I feel my Magnaflow sounds like, I just don't know how obnoxious it is or if there is anything to do to tone it down...