I am pretty sure this topic has been discussed numerous times and it has always been #1 recommendation to use Original Bosch Oxygen Sensors no matter what. That is exactly what I did but still have Error Codes.
1. Got Error Code for Bank 1/2 Fronts and Rears O2's
2. Replaced front Banks 1/2 with Bosch 13782 O2's. Drove for a while and was still getting Errors Bank 1/2 Rears
2. I have placed Aftermarket O2's on both rear banks and they failed after about 1 week. Well, I knew it but tried anyway.
The car has 202k miles and didn't want to spent a lot to make it to run for a few years.
2. Now I have decided to go with Universal Bosch 15738 while using connectors removed from aftermarket set. Match all wires correctly and secured them in place. Now, after 2 weeks of driving I am getting the same error again for Banks 1/2 Rear. Same code as before (don't remember the # from the top of my head).
Do Universal Bosch O2's are good enough for ML320, 98 or I need to get Bosch 13782? Perhaps maybe there is something else that I am not aware about. The passenger side has aftermarket Catalytic that is 2 years old while driver side is still original. Please help guys as I am due for a Smog Check in 1 month.