Kodiak74- You don't have to worry too much about excessive boost, becaus when the SES light comes on the MAP sensor is detecting out of range and it defuels a little bit over the stock settings. I'd recommend getting some gauges,(pyro and boost) that way you can watch it all. As far as how much boost is too much, I wouldn't go over 30psi. But the MAP sensor could trigger the SES as low as 20-22psi. Get some gauges and watch it, and then if is triggering the SES at 20psi or so get a relief valve to go inline to the MAP sensor. It will blow off any excess boost past about 25psi. I honestly didn't know what those were for until about a week or two ago. I'm running about 29psi of boost and it kicks on the SES all the time. I ordered one of those valves, the only problem is having to relocate the boost line to the intake manifold.