O2 Sensor Replacement for a Newbie

[Saintnick]

Hey Guys,

I recently purchased my first car, which happens to be a 2002 4Runner SR5. I absolutely love it and I look forward to modding it until it's very last days. Right now I have only replaced the headunit, speakers, and antenna, but I'm planning on changing the headlights, putting in fog lights, get some fender extenders (Black), and maybe even a K&N cold air intake.

I purchased the truck for $1200 with 142k miles and only a few mechanical issues with the brakes and engine light.

I am in the process of installing new rotors since the old ones were warped (Yes I know I should do the Tundra conversion, but then I wouldn't have a spare tire with my small budget) with some OEM replacement brembos.

The engine light has been on for the past year or so according to the previous owner, and when I scanned it I discovered it was an o2 sensor issue. I brought the code to napa after doing my own research and they said it was the Driver's side exhaust manifold bay 1, and it would be $260 to replace. Now that sort of money is extreme for my budget, so before replacing it I would like to get some more opinions on a plan of action from this forum. Thanks!

The error code was P1135 #10
Air - Fuel Sensor Heater Circuit Response Malfunction
(I'm assuming that this is also causing the traction and stability control lights to be on, as well as my garbage power and gas mileage due to the computer being in "Limp Home" mode.

Thanks Guys!
-Nick

 

[jeremyc74]

You can get the sensor for much cheaper than that, and it's not that hard to change.

First you need to figure out if your truck is a CA emissions vehicle or not. You can find this out by looking at the stickers on the underside of the hood, around the vacuum diagrams. The CA stuff is a little more expensive than parts for federalized vehicles, but we can point you in the right direction once we know what you have.

You need to stick with Denso sensors in this application. Denso is the company that manufactured the sensors for Toyota originally, and it's the same parts you'll get at the dealership, just about 1/3 the cost. Some of the other brands don't work right with the 4Runner, so it's not advisable to just pick them up at a parts store without knowing who made them.

 

[MONTYMTB]

He said it's a 2002, so that would automatically make it CA, correct?
This should be the part you need, but always verify before ordering:
http://www.amazon.com/Denso-234-9002-Oxygen-Sensor-Ratio/dp/B000C5YCYS/ref=cm_cr_pr_product_top

 

[jpeaslee]

I haven't had to do an O2 sensor on the T4R yet, but with my experiences I've had on other cars, as long as you spray it down with some PB blaster and let it soak a bit, it'll come right out. VERY easy to do yourself.

 

[jeremyc74]

He said it's a 2002, so that would automatically make it CA, correct?
This should be the part you need, but always verify before ordering:
Amazon.com: Denso 234-9002 Air Fuel Ratio Sensor: Automotive

I missed that it was a 2002, and I think you're absolutely right about that.

I bought one from the dealership here (before I started reading this forum on a regular basis) and I think I paid $165 for it.

 

[csp]

Yep that sensor on Amazon is the correct one. It's easy to replace, especially since it has a mounting flange instead of the sensor threading into a bung.

 

[Saintnick]

I'll check out that Anazon link and try to get it fixed next week! Thanks so much for all the help guys, you're awesome.

And it is a California Emissions vehicle.

Does anyone else have a different idea of what the code may mean, or is it definitely that specific sensor?

 

[jeremyc74]

I'll check out that Anazon link and try to get it fixed next week! Thanks so much for all the help guys, you're awesome.

And it is a California Emissions vehicle.

Does anyone else have a different idea of what the code may mean, or is it definitely that specific sensor?

If you get an A/F ratio code it can be other things, but since it's a heater code, it's almost certainly just a bad sensor. That's assuming the wiring is good between the ECU and the sensor. You can check the heater resistance with an ohm meter if you have one around.

Here's more info:
P0135 O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1 OBDII Engine Light Trouble Code | Engine-Codes.com

 

[WallyWest]

If you get an A/F ratio code it can be other things, but since it's a heater code, it's almost certainly just a bad sensor. That's assuming the wiring is good between the ECU and the sensor. You can check the heater resistance with an ohm meter if you have one around.

Definitely worth checking out. I had a similar code and it was the connector the sensor plugs into, one of the wires into the back of the sensor was frayed and almost totally disconnected.

You can get a connector and the wires from a dealer, splice it in to the existing wires. Cost me about $35.

 

[Saintnick]

I'll check out the connectors like you said, I'm crossing my fingers that that's the ultimate problem. I'll do a bit more research and some troubleshooting. Your information is amazing, thanks guys!

-Nick