Crank no spark I changed my spark plugs, ignition coils?

2005 CADILLAC STS
100,000 MILES • 4.6L • V8 • 2WD • AUTOMATIC
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JONBK_47
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I changed my spark plugs, ignition coils, radiator, and mass air flow sensor and car started up fine 3 times. I went to out the battery cover and when connecting the positive terminal, I heard a pop and the battery sparked the car did not start after that. I got a new battery checked the hood fuses and the rear seat fuses changed my starter relay and car still does not start, engine is getting fuel, but spark plugs are not getting spark. I thought it was my crankshaft position sensor but if my car started 3 times before the pop, I don’t think that would be the case.

These are the codes that are showing up:
P0442
P0300
P0420
P0455
P2108
P0521
P0106
P0101
P0068
P1101
P0326
P0331
P0700
P0102
P0113
Oct 2, 2024 at 10:56 PM
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STRAILER
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When you heard the pop, were the cables connected backwards? Usually this is the case when the cables are backwards. I would clear the codes and then turn the key on without cranking the engine over to see which codes come up, these are the ones that are causing most of the problems and we should address these first. Please go over this guide as well:

https://www.2carpros.com/articles/resolving-reverse-battery-connection-in-cars-a-step-by-step-repair-guide


Please go over this guide and get back to us.

Oct 3, 2024 at 10:14 AM
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JONBK_47
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No, the cables were connected correctly.
Oct 3, 2024 at 12:23 PM
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STRAILER
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Okay, did you clear the codes? If all of these codes came on at once I would think the PCM is bad.

P0442: Evaporative Emission Control System Leak (small).
P0300: Random/Multiple Cylinder Misfire Detected.
P0420: Catalyst System Efficiency Below Threshold (Bank 1).
P0455: Evaporative Emission Control System Leak (large).
P2108: Throttle Actuator Control Module Performance.
P0521: Engine Oil Pressure Sensor Range/Performance Problem.
P0106: Manifold Absolute Pressure (MAP) Sensor Range/Performance Problem.
P0101: Mass Airflow (MAF) Circuit Range/Performance Problem.
P0068: MAP/MAF - Throttle Position Correlation.
P1101: Intake Air Flow System Performance.
P0326: Knock Sensor 1 Circuit Range/Performance Problem (Bank 1).
P0331: Knock Sensor 2 Circuit Range/Performance Problem (Bank 2).
P0700: Transmission Control System Malfunction.
P0102: Mass Airflow (MAF) Circuit Low Input.
P0113: Intake Air Temperature Sensor 1 Circuit High Input.

Has the wiring been tampered with? Also, you may have corrosion at the PCM electrical connectors so please check for that as well. If the fuses are okay (test with ignition on) I have left the location and instructions on how to change out the PCM, you can get a preprogrammed unit by searching Google or Ebay. Check out the images (below). Please upload pictures or videos in your response of any problems so we can see what to help you with.

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Oct 4, 2024 at 11:06 AM