Hello everyone. I have just finished my engine swap in my 2003 ford focus zx3 and after starting up the car it idles around 2kRPM and then after 10sec later jumps straight up too around 4kRPM I spent a whole day seeing if I did anything wrong or left anything unhooked. I even did a vacumn leak test by pushing smoke into one of the vacumn lines and spraying starter fluid around all seals example intake manifold, throttle body, vacumn lines. Anyways I know the IAT is built into the MAF sensor so I decided too unplug the MAF sensor and now my car idles fine. Before it idled so bad that if I was in gear and took my foot off the brake the car would take off! So in conclusion I believe it is a really bad MAF and IAT giving false readings and when I unplug the sensor the car just goes too its pre-determined map. What is everyone elses thoughts on this?