Denso234-9001 Upstream Air Fuel Ratio Oxygen Sensor with 10.6” 4-Wire Harness, for Auto Trans Equipped Vehicles

I have a 2003 Toyota Tacoma, 2.4L, 5-speed manual transmission. It threw a check engine light, with the code being P0135, relating to the oxygen sensor, specifically the air/fuel ratio sensor. Toyota uses Denso as it's supplier of parts, and this is the exact replacement part, the only difference being that it does not have the Toyota logo on it. I found this part at a major auto parts retailer for almost $80 more, but I figured I would google the part number. Did not expect to find it on Amazon, and certainly not for $80 less. Anyway, this product is a direct replacement for the original part, and it includes the gasket as well. The only thing you will need extra is WD40 or similar penetrating lubricant spray, and a little bit of anti-seize compound to put on the threads before tightening the new sensor. There are 2 sensors on my truck, the A/F sensor is the one that is in front of the catalytic converter, and the basic oxygen sensor is behind it. I was replacing the A/F sensor due to the P0135 code.Basic procedure:1 - make sure you allow the exhaust pipe to completely cool2 - Spray the 2 nuts that hold the sensor on with WD40 or similar and wait a few mins for it to penetrate3 - Use a 12 mm socket or wrench to remove the bolts and disconnect the electrical plug from the harness (hint: there is a tab at the top of the harness. Squeeze it and pull the plug out. You may need to wiggle it, but it will come off with no problem).4 - Note how the original gasket was placed, throw away the original, and place the new gasket with the correct side down. It should be the side that has more of the white material exposed.5 - Place the sensor on the bolt studs, coat the threads with anti-seize compound, and tighten the nuts. Don't over-tighten, but make sure the sensor is tight on it's seat so exhaust doesn't leak past it.Overall, it is a very easy job that took me no more than 20 mins. I didn't even have to raise the truck, but if you do, make sure it is securely supported using jack stands or ramps, set the parking brake, and block the wheels. Do not get under it with just a jack holding it up. Since I don't have a scan tool, I pulled the negative battery cable to reset the check engine light, and that was it.

1) Amazon has the best price I could find anywhere for this product2) installed it on a 2002 Toyota Tacoma 3.4L V-6 4WD Double Cab Automatic; upstream sensor (right after the engine, before the two catalytic converters). Location is readily visible if you crawl under the truck on the passenger side, right after where the exhaust pipes from either side of the engine come together on the underside of the truck.3) Used PB Blaster to help loosen EXTREMELY rusty nuts; this product works wonderfully (just use latex gloves).4) 12mm nuts, was able to reach them with a deep socket - the socket is the only tool needed for this repair (you don't need an oxygen sensor wrench)5) Used Permatex Anti-seize lubricant on the threads when placing the nuts back on to tighten the air/fuel sensor to the exhaust pipe - 14 ft lbs of torque for the nuts (the threads are the two bolts permanently mounted to the flange on either side of the air/fuel sensor). Permatex is a very good product which has a temperature range of -60°F to 1600°F (-51°Cto 871°C) and is salt, corrosion and moisture resistant.6) disconnected the battery before doing the repair (remember to disconnect the NEGATIVE side of the battery).7) the electrical connection has four wires; the two black wires can be checked with an ohm meter (open/OL/high resistance is bad, should be 11-16 ohms). I used a 10mm socket to remove the bolt for the metal support for the female side of the connector; the connector has a rocker-arm on top which locks it in place - mine was pretty hard to press down so removing the bolt allowed me to get a better grip on it, made the repair much easier.8) The gasket should be oriented with the part having the most white facing toward the exhaust pipe9) DON'T TOUCH THE SENSOR TO ANYTHING at all when you install it - prevent grease/oil/lubricants from getting on it10) the error code I had was p1135 - P1135 A/F Sensor Heater Circuit Malfunction (Bank #1 Sensor #1); my truck only has two sensors, one upstream (before the catalytic converters) and one downstream (after the two catalytic converters but before the muffler).11) I am having to install the downstream (rear) sensor as it failed 3 days after I installed the upstream sensor. Glad I ordered them both at the same time! The downstream sensor required me to buy a new intermediate pipe (WALKER Part # 53398) as the old pipe had rusted out where the oxygen sensor gets attached to the flange on the pipe. A perfect place to find all the parts to your exhaust is rockauto(dot)com, look under exhaust>pipe and click on the blue square with white lettering that says "info"Hope this helps someone out there!

Cheaper than the dealer and any parts counter and it’s oem

It did what is was supposed too and fixed the problem

Denso sensor, works awesome! There's a reason why this is a Toyota OEM part.Fit my 2002 Toyota Tacoma like a glove. In case you're not sure, this is the sensor AFTER the cat, not the O2 sensor before it.

This part worked for my Tacoma and appears to be a genuine Denso part.Check engine light was deleted after install and it has not come back on after 3 months of driving.This part is for the sensor located upstream of the catalytic converter. 02 sensor is downstream.

Proper fit and the right unit as it was identified to be. So much cheaper than at dealership! Toyota Dealer is a robber!