: 99 eldorado 02 sensors

07-06-14, 03:29 AM
Can someone tell me how many o2 sensors are in a 99 cadillac eldorado are and there location in the vehicle please??

07-06-14, 10:03 AM
You probably have 4.

Bank 1 is the right (rear) cylinder bank
Bank 2 is the left (front) cylinder bank

B2S1 is in the left bank exhaust manifold collector
B1S1 is in the right bank exhaust manifold top
B1S2 is in the pipe just ahead of the cat
B1S3 is in the pipe just after the cat

In the 2000 and later engines there is no pre-cat sensor, so the after-cat one becomes B1S2.

07-06-14, 08:39 PM
Wouldn't swear to it, but I seem to recall Cadillac dropping the pre-CAT sensor between '98 & '00 (my '97 still had it).