2000 Chevy Venture 3.4L P0336B Code: Stalling, Backfiring, and Idle Miss - Diagnosis & Solutions

My 2000 Chevrolet Venture with a 3.4L engine has been experiencing persistent drivability issues despite multiple repairs. Initially, a camshaft position sensor fault (P0336) resolved after replacement, but intermittent symptoms such as stalling, severe backfiring, failure to stay running, and noticeable idle miss have persisted. The symptoms occur unpredictably—sometimes after just one mile, other times after 60 miles—during both cold starts and warm-up periods. Between episodes, the vehicle runs perfectly. Fuel rail pressure readings remain normal, and I've confirmed that the spark plugs are in excellent condition with no signs of wear. To rule out further electrical issues, I replaced both crankshaft position sensors and had the ECU professionally inspected and repaired. The problem remained unresolved. During a 1200-mile trip, the issue recurred and generated new diagnostic codes: P0300B, P1620C, P1374B, and finally P0336B (with 'B' indicating the second sensor bank). I then inspected the ignition control module (ICM), checking for carbon tracking and resistance values—everything appeared normal. However, I replaced the ICM due to inability to test it under real driving conditions. After clearing codes and conducting a test drive with the OTC Enhanced 4000 ECU plugged in, I observed that the 24x sensor (camshaft position sensor) reading would occasionally spike to over 3000 RPM—once exceeding 4000 RPM—and drop to zero. At times, the system reported 'No Data' while still driving. The P0336B code reset repeatedly, even before engine restarts. The 24x sensor reading typically lags behind actual engine RPM by only 20–50 RPM during operation, but it does not match consistently with engine speed. I've also checked for short circuits to ground on the ignition power supply to the camshaft sensor—no issues found per Mitchell On Demand recommendations. Given this, I'm now questioning whether a defective 24x sensor could be the root cause. What other factors might I have missed? Is there a known wiring or ECU interaction issue with the 3.4L engine in early 2000s Ventures that could explain these erratic readings and drivability problems?