I have a 2005 Mazda 6s with 109k miles.. Just had engine replaced with a refurbished one, car also has egr re route, MSDS headers, and magnaflow cat back. The problem only happens when its stopped or coming to a stop. I have CEL codes p2195/ p2197. I did a smoke test for vacuum leaks and saw a leak by the throttle body, I noticed its chipped a little bit in the corner too, cleaned it and replaced the gasket, problem still persist. New MAF, the 02 sensors are not faulty, and the intake accordion hose is not cracked. Any advice/ ideas would be greatly appreciated!