My 5.7 has been cutting out lately. Everything under the hood is new except for the MAF,CTS and FPR. It can be 70 degrees in the morning and I will let the car warm up for say 30 seconds, and when I give it light throttle, it cuts off. Then it may be fine the rest of the day. It has done it while it was hot, so I dont think its temp related. NOW, 1 or 2 of the plug wires got on the manifold so I had some arcing but I have them out of the way until I get new ones on. That may be one cause. Also, the FPR tested at 38 psi with key on and about 36 running. May be a combination of things. Base timing and TPS are all correct, so no looking there. Im leaning towards the plug wires. Seems it started up after they got burned a little. New engine, by the way. No codes either.