I have been working on my mother's Impala lately with cylinder 4 misfire which turned out to be a bad wire going to the injector. At 175k or so I did PCV and fitted line broke, as well as spark plugs. Found the purge valve line loose fitting so I ordered purge control valve and line. While getting electrical connector off it broke in my hand so I repaired it. While I had to remove intake for 3rd time I broke map sensor. I replaced both map and purge with aftermarket. Vehicle had no check engine lights after work was completed. Fast forward 2 months and lean code bank one so I found line for PCV was not fitting tightly enough so I put new line on. Checked fuel trim perfect now. 2 weeks later I get fuel trim imbalance bank 1 and bank 2. Found bank 2 02 sensor rich and bank 1 Normal but didn't want to throw an O2 sensor in yet so I pulled beauty cover off and there was a loud ticking from new purge valve. I just replace valve and electrical connector then test drove. Fuel trim is beautiful and 02 sensor is cycling as well. I did replace the purge valve with AC Delco however it had Bosch name on it. Parts are not only getting worse the vehicles are super sensitive to failures. When I retired almost 20 years ago you either had a shake or bad fuel mileage which showed something was wrong. This is 3rd part that has failed in a year.