Mercedes W210 E280 P0135 and P0150 Fault Codes - Bosch ECU Diagnosis and Solutions

Hi everyone, I'm experiencing a recurring issue with my Mercedes W210 E280. The vehicle is showing pending diagnostic trouble codes (DTCs): P0135 and P0150, along with a logged P0300 misfire code. I've already replaced the following components: Bank 1 Sensor 1, Bank 2 Sensor 2, both post-catalyst oxygen sensors, Bosch MAF sensor, vacuum hoses, temperature sender, battery, alternator, and air filter. The issue is intermittent and primarily occurs during cold starts. After turning off the engine and restarting it multiple times (typically 3-5 times), the symptoms usually resolve within a few miles. However, the check engine light remains on, and misfire codes are frequently logged—most commonly for Bank 1 Sensor 1, though Bank 2 Sensor 1 can also appear. The fault seems to be related to sensor performance under cold conditions, especially with the Bosch ECU managing fuel trim and ignition timing. I'm seeking advice on potential root causes or further diagnostic steps that might resolve this issue without replacing additional sensors unnecessarily. Any insights from owners of W210 E280s with similar issues would be greatly appreciated. Paul