delphi or delco are usually the better ones to get, but i think i would see if i knew anyone that had a heat gun i could borrow and test it. the crank sensor isnt that bad price wise but you didnt say what your car was but the older 3800'* with the all in one icm/coils are kind of pricey to just replace. i would look on rock auto and that and see what you want to do. when my ckp went on my 90 it didnt ever give a cel. and when the icm went on my 88 it didnt through a code. most times thats what it is. less likely but possible is the wiring between the two.
1998 Bonneville SSE
2007 Monte Carlo LT-KYB, Clarion, Polk audio, Kicker
1999 Yukon SLE-KYB, Air lift, Reese dual-cam, Tekonsha
1987 Firebird-355/th400-nothing stock