GreaseGirl, a couple of things.
First, the P1345 DTC IS NOT for "Electrical Short: Ignition Coil Output Stage 3" as you stated. P1345 is for a Camshaft To Crankshaft Position Correlation Fault, which goes along with a bad VVT Solenoid and the P0014 DTC.
So, perhaps you do not have a defective ignition coil (especially since you do not mention either a P0300 or P0303 code being present).
Second thing. Please use a decent quality 5W30 motor oil along with a decent oil filter. I would not use a 10w30 oil because the VVT is designed for a 5w30 oil and the operation of the VVT solenoid is dependent upon clean 5w30 motor oil, not 10W30. By the way, almost every motor oil today (except for the never heard of brands sold at some convenience stores) meets the oil specification for the TrailBlazer 4.2 engine. So, go to Walmart and purchase pretty much any oil from Walmart's SuperTech 5w30 to Mobil 1's most expensive 5w30, and either a SuperTech, Fram, Purolator, ACDelco, or Wix filter and you'll be just fine.
Good Luck!
First, the P1345 DTC IS NOT for "Electrical Short: Ignition Coil Output Stage 3" as you stated. P1345 is for a Camshaft To Crankshaft Position Correlation Fault, which goes along with a bad VVT Solenoid and the P0014 DTC.
So, perhaps you do not have a defective ignition coil (especially since you do not mention either a P0300 or P0303 code being present).
Second thing. Please use a decent quality 5W30 motor oil along with a decent oil filter. I would not use a 10w30 oil because the VVT is designed for a 5w30 oil and the operation of the VVT solenoid is dependent upon clean 5w30 motor oil, not 10W30. By the way, almost every motor oil today (except for the never heard of brands sold at some convenience stores) meets the oil specification for the TrailBlazer 4.2 engine. So, go to Walmart and purchase pretty much any oil from Walmart's SuperTech 5w30 to Mobil 1's most expensive 5w30, and either a SuperTech, Fram, Purolator, ACDelco, or Wix filter and you'll be just fine.
Good Luck!