After Cat fuel trim Error
 

I have an E53 / M54. I just changed pre and post O2 sensors for # 4 -6 bank. I did not get wires crossed. Error E2 came on. Can anybody please help? Thanks!

Pre & Post CAT O2 Sensors
 

I have an E53 / M54. I just changed pre and post O2 sensors for # 4 -6 bank. I did not get wires crossed. Error E2 came on. Can anybody please help? Thanks!

Thanks trader4 -

I have a BavAuto code reader and code E2 from table 19 says, "After CAT Fuel Trim".

What O2 sensors did you use?

Could it mean "after cat O2 sensor trim"?

Bosch

Did you have the E2 code or any other before you changed the sensors?

Could be the efficiency of the cat for that bank. The post cat 02 sensor doesn't control fuel trim like pre cat 02 sensors. One simple test to perform is if you have an infrared thermometer is to drive the car until the temp is up and use the infrared thermometer to measure the temp at the inlet of the cat and at the outlet of the cat. The outlet temp should be greater then the inlet temp if the cat is working properly.