Hey I'm back for the same vehicle 03 GMC Envoy I need to know where does the transmission tube goes into the transmission I pulled it out trying to change my O2 sensor in the front where the manifold is located can someone help me please

SOURCE: I need to know how

It would be to hard to tell and show you over the computer.
The best and easiest way for you is to buy a Chilton manual for your car at the autoparts store. The book runs about $20
This book is a do-it-yourself bible. It will show you everything you need to know on how to do maintenance and repair on your vehicle.

SOURCE: 2004 Chevy Blazer O2 Sensor

there are two 02 sensors actually on the engine. bank one is cylinders 1 3 5 bank 2 is 2 4 6. it controls the fuel to air ratio, if the O2 sensor is not working, the engine goes into limp mode, which means it is just putting as much fuel as possible into the cylinder, which will effect your gas mileage.

The O2 sensor may be fine, the pigtails off the 02 sensor go bad, the connection. I had in my car, i change the 02 sensor twice, then I found someone said the pigtails may be bad, so I cut the cars wiring harness pigtail, and the one coming off the 02 sensor, and directly wired it with the original truck 02 sensor, and it worked. all 02 sensors look similar, they screw in the side of the engine, and just have 4 wires coming off of it.

Try your origional one, and just bypassing the original wire connector, what I did was cut it off, skinned the wires, put some heat shrink rap on it, combined the wires together soldered them together, and heated the wire shrink rap, so that way it is water proof. car works perfect now.

SOURCE: check engine light....coolant temperature sensor

take altanator off and it is located right behind

Johnny Brown

• 5763 Answers
• Posted on Jun 21, 2010

SOURCE: where is coolant temp sensor located on 2003 gmc

heres a diagram to show you where the coolant temp sensor is located, its behind the alternator on the left side (driverside),the sensor just unplug the connector and then unscrew it and out it comes.

SOURCE: 1999 GMC Tahoe 5.7L engine trying to locate O2

Hi, There are 4 sensors, 2 pre catalytic converter, 2 post. The driver side is bank 1, and the passenger side is bank 2 .The foreward one in the pipe coming from the driver side is bank1 sensor 1, the rear sensor for the driver side is bank 1 sensor 2 . The other side would be the same, but bank 2. Good luck...