2002 Ford F-150 rattle sound when accelarating

Here is from out tips page. Also check fuel pressure with a gauge auto parts rent it
If you get one of these vehicles in your shop with the MIL on and the following codes P0174 or P0171, P1131, P1151. Make sure and have a look at the Upper intake isolator bolts. If you are test driving the vehicle and are testing it while it is hot you are not likely to see any problem with the fuel trim or 02's. However fire it up cold and it should be quite obvious on the scanner and with a smoke machine. Make sure you replace all the isolator bolts with the new and improved ones (green new style / old style black). Also a good idea while you have it tore down to do the port seals and top seal on the intake. Good Luck!