Keith, I had the same problem with the maf I purchased from MM. With my chip installed the car would detonate like no tomorrow, without the chip it would "surge"(lack of fuel). Luckily I had ordered the remote optimizer at the same time, I had to dial it in full rich at the high speed setting just to get it to not detonate. Then about a month down the road the maf optimizer broke(looked used when I got it!), so then I was SOL. Sold the maf and gave the optimizer with it for free. My personal feeling is that Muscle Motors doesn't question the NECESSARY info like factory maf serial number, build date, engine mods etc.. All they ask for is factory or cold air inake? If I purchase another maf it will be from SP, and hopefully it will work correctly.
