Sensor 1, Bank 1.

[1996GMCJimmy]

Hello,
I recently had my 1996 GMC S-15 Jimmy checked out because of a SERVICE ENGIGE SOON light, it turned out the proble is the Snsor 1, Ban1 that needs replacement. I know its an O2 sensor that needs replacement, but can anybody let me know where this SENSOR 1, BANK 1 sensor is localted? Thanks a lot!

[Jeremy-WI]

Follow exhaust on the drivers side of the engine from the exhaust manifold back, it will be the first one.

In case you want to know Bank 2 sensor 1 is the closest to the engine on the passenger side
Bank 1 sensor 2 is the one between the y pipe and catalytic converter and bank 1 sensor 3 is the one between cat and muffler. This info is for a single cat exhaust which was pretty much standard on the 4.3 or 5.0

[1996GMCJimmy]

Jeremy-WI,
Thank you so much! Your input helps a lot, especially knowing where the rest of these sensor are also located.

[BlazerLT]

What did the code say?

Not all O2 sensor codes mean you have to replace the sensor.

[1996GMCJimmy]

Originally Posted by BlazerLT

What did the code say?

Not all O2 sensor codes mean you have to replace the sensor.

************************************************** **
Hello BlazerLT:

The code read as follows:

P0133
O2 Sensor CKT Slow Response (Bank 1, Sensor 1)

Thank you for your input!

[BlazerLT]

Welp, in this case, yes, looks like the O2 sensor is lacking a lot.

Swap it out.