i've just completed an engine swap on an 02' neon r/t and it fired up just fine the first time and after about 350 miles it died on me while i was on the highway and threw 2 codes at me which were p0340 and p1391 ive replaced both CSP and CKP sensors and after changing the crankshaft position sensor it started up 3 different times and each time when i would go to put it into gear and let off the clutch it would die and now after the 3rd time it will not turn on again.

I NEED HELP PLEASE.

 

since it ran before the swap it will most likely be the crank sensor, both codes show a malfunction in the ignition system and Chrysler products are notorious for defective crank sensors, but triple check all the wiring harness grounds first to make sure you did not miss any when installing engine..