1997 Chevrolet Blazer P0300 and P1441 Fault: Symptoms, Causes, and Solutions

I own a 1997 Chevrolet Blazer with a 4.3L engine and 165,000 miles. Approximately four months ago, the fuel pump failed, so I had it replaced at the dealer along with a full fuel system cleaning. Shortly after this service, I started experiencing a noticeable engine shudder during low-speed acceleration—especially around shift points and when pulling away from stop signs. The vehicle also stalled two to three times while accelerating from a complete stop. Recently, the 'Check Engine' light has come on intermittently, accompanied by diagnostic codes P0300 (random/multiple cylinder misfire) and P1441 (fuel level sensor circuit malfunction). I have avoided replacing spark plugs or ignition wires because I recently completed a full replacement of all components—including spark plugs, wires, distributor cap, and rotor—back in November. Since then, the vehicle has run smoothly at higher speeds. However, these recurring issues are concerning. Does anyone else have experience with similar symptoms on this model? Any insights into potential root causes or troubleshooting steps would be greatly appreciated.