I need some feedback. I've been running stage 1 pipes & breather with Harley's chip upgrade with no problems. This season I changed over to S&S gear drive primary with Andrew's 21g cams. I've been getting the pinging since the change & I get a strong exhaust smell during cold engine idle. I think that a fuel mangement system will cure it. I'm not sure of where to go. Power Comander, Fuel Pack, or ? Any feedback ?