Help needed fast! Truck wont start or run

[justin95]

I have a 1999 GMC Yukon with the 5.7. I rebuilt the motor about 800 miles ago with new parts, the upgraded MPI injectors, mid-length headers, Magnaflow high flow cats and new o2 sensors and Magnaflow muffler. Truck ran awesome until 5 days ago i started it ran fine then died 100 ft from my driveway and wouldnt start again. i read the codes and came up with p0102 Maf sensor low input and looked at fuel pressure. The fuel pressure was low so i replaced the fuel pump, MAF sensor and map sensor and checked all my wiring and my truck still wont start. Ive spent tons of money lately in it lately and i am stumped why it wont start or run. i have found answers to other problems on this forum so im hoping you guys can help me out. Thanks

 

[lesterl]

Unplug the electrical on the MAF, see if it will start. Check CKP sensor in timing chain cover.