1997 Chevy 1500 Express Van

[Pellerito]

Where are the O2 sensors located and how many (pre and post CAT?)

[MT-2500]

Originally Posted by Pellerito

Where are the O2 sensors located and how many (pre and post CAT?)

Engine and engine code?

Pre cat sensors in front of cat.
Post sensors behind cat.
Bank 1 sensor 1 front sensor on left side of engine.
Bank 2 sensors are in right side exhaust.
Bank 1 sensor 2 will be in front of cat.
Bank 1 sensor 3 is usually behind cat.

[MT-2500]

Why are you asking locations?
any codes or problems with them?
Code no?
And what engine and transmission and engine code?