Replace the Oxygen Sensors (O2 Sensors) on a 1995-2004 (First Generation) Toyota Tacoma 3.4L

Works For:
1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Toyota Tacoma 3.4L Models

Source: LIEBLWEB

Vehicle Information: 1996 Toyota Tacoma, manual transmission, 4WD 3.4L V6, 74,000 miles
These are basic instructions on how to replace the Bank 1 Sensor 1 Oxygen sensor.
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Use this information AT YOUR OWN RISK!

Troubleshooting: The Check Engine light…..a Do-it-yourselfer’s nightmare. I don’t have an engine code reader – so I decided to research on the internet for some ideas and try to save myself that dreaded trip to the dealership for repairs. ** I found a really neat website that tells you how to use a wire/paperclip to check the engine codes. I actually tried this method on my tacoma and instead of the ‘blinking’ check engine light, I got the door chime instead. I was able to pull the proper code to tell me it was the Oxygen sensor. However – there are two oxygen sensors on the tacoma. How do you know which one (Bank 1 Sensor 1 and Bank 1 Sensor 2)?? These sensors are important to making your engine run smoothly and cleanly. Here is a brief paragraph from the Toyota Service Manual Click Here. Since this didn’t really tell me what I wanted to know and I didn’t want to spend the money on an O2 sensor from the dealership unless I knew exactly which one was bad, I paid a visit to the dealer and paid them $30 for them to tell me exactly which sensor needed replaced.

Parts Needed & Other Information: Toyota Part # 89465-39895.  This part includes sensor and replacement gasket.  No replacement nuts.  We ordered it from Conicelli Toyota www.partznet.com. Make sure when ordering any parts that they are specific to YOUR application.

Description & Location

Bank 1 Sensor 1

Description & Location

Bank 1 Sensor 2

Preparation

We have a lot of rust, so for 3 days ahead of the time, I sprayed the nuts with penetrating lubricant to help with the installation. I did not want to risk ripping or breaking a bolt on the exhaust.

Bank 1 Sensor 1 Cord Location

Cord Removal
Step 1:
We tried to reach above the transmission to disconnect the chord, but there just wasn’t enough room and you can’t see anything up there. So we decided to get to it from the shifter console. Start by removing the shifter knobs by unscrewing them. Remove all 4 screws that hold the console cover and remove the console cover.

Cord Removal
Step 2:
After removing the console cover, remove the 4 screws and remove the shifter boot assembly. The pictures below will show you where the chord is located.

Cord Removal
Step 3:
The part of the connector you need to access is facing towards the front of the truck (and away from you in the cab).  The connector is also attached to a clip that is attached to the tranmission. We broke the plastic clip that was holding the connector in place (on purpose).  This enabled us to swing the connector around which gave us plenty of room to disconnect it.

Cord Installation:
After disconnecting the old chord, we connected the new one and carefully fed the new sensor down through the hole in the cab.  We did not bother to clip the chord on the transmission.

Oxygen Sensor Removal:
At this point, you have a new oxygen sensor hanging from above the transmission and you still need to remove the old sensor. The old sensor is only held on by 2 nuts. The studs are a part of the exhaust. Be very careful when removing these nuts not to twist, bend,cross-thread, or break the studs. If you have trouble removing the nuts, use penetrating lubricant and lots of patience. Or – you can also heat the nuts with a torch. Be careful NOT to round the corners of the nuts because you will need to use these again when installing the new sensor. I purchased new nuts and lockwashers for the installation.

After removing the old oxygen sensor, clean the surface and remove the old gasket material. Install the new gasket material first and then apply the oxygen sensor making sure its in the same orientation as the old one. Use some Anti-Seize lubricant on the threads of the studs. Apply the nuts and tighten.

That’s It!!

Please – Be Safe – Be Patient – and Good Luck!