Problem has been trying to pick up speed the way the 4.9 intends to. Not racing or nothing but I cant even try to go around a slow driver on the highway without worrying about being rear-ended because my car wont pick up speed when I choose. Its hard to explain but when giving it gas it wants to go but before it even tries it will back down try again back down until i just give in. Reminds me of when I'm below 5 gallons of gas and trying to merge onto the highway.( I gotta a bad tank ) But this problem is with a full tank. Doing my readings on here, some ppl suggest MAF or MAP or COMPLETE TUNE UP and fuel pump and alternator timing ( something like that ). I ran the codes and deleted them. E39 - E75 - E98, drove around for about 10 mins giving it some gas and the codes havent returned. What do you guys think?