The only thing Blackstone bagged on for me was Si content. They say check my air filtration, but I think I know what the real culprit is: my disintegrating left precat. Not excessive, 31 ppm.
If I could just get a yard to actually tell me that they warrant the d**n precats, even for just 30 days, I could buy one. I'm getting the following response, from more than one yard: "We sell the cat converter at extra cost, not included with the manifold."
