P0134 and P0175 codes, help

[Adijax]

Hey guys, its been forever since i posted on here. I purchased a 03 525i with 163k from a private seller and it needs some work. I took care for most of the issues it had but this one i just cant figure out. The car has the Bank 1 Sensor 1 code i just cant get rid off. The O2 sensor is new and its Bosch. This is what iv'e done so far

1. Checked out the connector and the pins ( O2 side )
2. Swapped sensor 1 with sensor 2 and i'm getting the same code
3. Checked the plug, pins on the DME and cleaned them
4. Reset all adaptation using ISTA+
5. Reset the whole car using ISTA+
6. Ran O2 tests using ISTA+ and it failed with bank 1 sensor 1

If i drive for a while i get occasionally codes for bank 2 sensor 1 and 2 heater and bank 2 rich

Please let me know what i'm missing here.

Thanks

[Jaaap]

Sounds like a wiring issue.
Does the car run good?

[JimLev]

Have you looked at the fuel trim numbers?
Your MAF could be causing both of those codes.

[E39 Newbie]

+1 on the MAF. I just had to replace a brand new Bremi unit with a brand new VDO unit. The Bremi was causing all sorts of funky "too rich" errors. Similar issue in my Mustang. Bad "Brand X" MAF installed by PO was causing all sorts of rich and lean conditions.