Hmm...

[DeefNDorf]

Hmmm..Ok..changed my o2 sensor...got the banks thanks to my diog. comp...jst unplugged em till I found it...bank one is 1-3 cyl..and bank two is 4-6 cyl...number one is before cat..and number two is after the cat...so sensor two bank two..is off the 4-6 cyl..and behind the cat....

[93 325i]

wow im confused.....

[dutchbmw]

What when the DME is bad.....

[DeefNDorf]

Hmm..Well my car has four O2 sensors....when my check engine light came on the diog. said sensor two at bank two malfunction..now stay with me....bank one is 1-3 cyl..and bank two is 3-6 cyl...look under the hood you can see em....and each bank has two sensors..one on the manifold..and one after the cat...so bank two sensor two means...exhaust comen off the 3-6 cyl..and after the cat..see its easy..if anybody gets this error with a diog...just pm the location and Ill tell you were its at...

[Brian325i]

What year and model do you have...I thought when you replace your o2 sensor...you only need to replace one. There are 4 o2 sensors?

[93 325i]

OBDII's have 4 O2 sensors..pre 95's have just 1

[DeefNDorf]

Hmm..some have two..just depends...but when replacing one it can be very confusing...