Chevy blazer

looking for bank 1 sensor 2

Bank 1 is the side of the engine that cylinder #1 is located. Sensor #2 is the O2 sensor after the catalytic converter on that side of the engine.

Tester

ok there are four o2 sesors on there one on each side of the y pipe and one before the cat and after so u say it will be after the cat

Yes. The O2 sensor before the cat is sensor #1. The sensor after the cat is sensor #2.

Tester