NO won't be speed sensor as it does it when stationary, try cleaning the ISCV, have a look at the rear of the underside of corner of head, where the pipe from the front mounted PCV valve meets the "T" piece, well known for perishing, causing air leak and weak mixture.
Clean the MAF, with carb cleaner, then reset KAM fuse in fusebox, a violet 2 amp one.
tabetha