Elsewhere in threads re: smoke, is a discussion of the EGR and how to fix it when stuck open. Story goes like this: EGR is vacuum actuated and can stick in open position when you floor the accelerator to pull away from stop. Result: partially burned mixture is cycled back through intake and dumped into new charge in combustion chamber, creating an overly rich (i.e oxy-starved) mixture that does not fully burn-which then is recycled again through open EGR. This will make lots of smoke til the turbo spools up and solves the fuel-air ratio. Mr. MB (Enrique to fans) at his shop in Tarzana did the famous BB fix for me and it changed my 300 CDT quite elegantly, no smoke and lots of go. Oh, the BB fix: put a BB in the vacuum line to the EGR, preventing vacuum from opening it. Just make sure the BB is large enough to stay put and not suck upstream. If this makes you feel guilty, replace the EGR because the BB workaround will increase NOX. Don't know of any other serious side effects and in my case, my 300 burns soybean oil. Congrats on your beautiful 300CDT, aren't they splendid!