I want to try to reach out to the pros one more time. I have read every single post on this site about 4 times that has p026d mentioned and I'm still clueless about what is going on. I've had an assortment of engine-related issues since I've owned it, so I purchased the recent GDE EPA compliant tune. That seemed to keep a lot of issues away for a while until I received this pesky p026d code. I've talked with GDE a couple times about it with no real answer. I've switched back to the stock tune and driven hundreds of miles with many starts and the CEL won't come back on with the stock tune. I've cleared the code on GDE tune and it comes back on within 2 starts. I just recently pulled the MAP sensor and cleaned it. It was dirty but not completely clogged. It actually drove 80 miles and 5 starts before CEL came back on this time (which is an improvement). But I'm not sure what else to check. Fuel filter is the next option that I've read about. Anybody else have any ideas? Is there such thing as a bad GDE tune? Or do they do any updates that may be able to fix it?