3rd Gen 4Runner O2 Sensors (1 Viewer)

Joined
Nov 14, 2007
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34
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Grants Pass
Hey all,

I'm currently working through a CEL Code p0171 issue. I've cleaned the MAF sensor, cleaned the throttle body with the (EXPENSIVE) 3M cleaner kit, replaced the spark plugs and wires (spend the money and get yourself NGK P/N BKR5EKB-11 for the plugs), and have now replaced the upstream Oxygen Sensor (actually called the "Air/Fuel Ratio Sensor Toyota P/N 89467-35011)...Still setting off the CEL with p0171 after being reset and is idling rough...

ANYWAY, I'm writing to tell everyone that if you need Oxygen sensors you should just do your research and find the Denso equivalents (as this is what toyota shipped me). You'll save a Sh@t ton of money. Here they are on amazon.com:

Upstream Sensor

Amazon.com: Denso 234-9002 Air and Fuel Sensor: Automotive

Downstream Sensor

Amazon.com: Denso 234-4622 Oxygen Sensor: Automotive

Hope this helps someone (wish I'd known),

RH01

Also, in case you want it, the downstream oxygen sensor is Toyota P/N 89465-35580.
 
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Joined
Jan 10, 2009
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286
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Decatur,AL
I had the same code on my daughters 4runner and had started the process. If my memory serves me well it seems like I could reset the code and it would only come back if you were to drive on the hwy, shut the engine off and get back on the hwy.

I had also cleaned the MAF. Then she totaled it and I never really knew what was going on. Please post up if you find a solution.
 
Joined
Nov 14, 2007
Messages
34
Location
Grants Pass
CEL update (little one)

mmml4, I've got the same issue with it being reset and then coming on again on the highway after being turned off. Unfortunately, I live off a highway... I stopped in at the local dealership to see if they had any advice. The service guy said they'd done "thousands of these" over the years and it was invariably the MAF Sensor being dirty and that I should clean it again. So I did... Still P0171... I've got the downstream sensor on order. Hoping this works... I'm getting tired of the rough idle and have other projects to work on... Like the amazing Toyota 4Runner warped rotors problem.

I'll keep updating as long as people care,

RH01
 
Joined
Nov 14, 2007
Messages
34
Location
Grants Pass
Thanks for the help!

LukeZero,

Any advice on a particular route to go on the rotors? I like the idea of the upgraded toyota pads, but if possible I'd like to avoid $140 in Brembo rotors. The forum you posted has a few options, I'm just curious if you've had any experience.


raydouble,

Thanks for the ODII code list. By ECT do you mean ECM? and how would I go about testing both that and the MAF? I'm gonna look into getting the PCV now. OEM, of course (damn the japanese for making superior products and delicious sushi).

Thanks for the help guys,

RH01
 
Joined
Feb 11, 2008
Messages
1,524
Location
Rochester, WA
raydouble,

Thanks for the ODII code list. By ECT do you mean ECM? and how would I go about testing both that and the MAF? I'm gonna look into getting the PCV now. OEM, of course (damn the japanese for making superior products and delicious sushi).

Thanks for the help guys,

RH01

The coolant temp sensor.

You can find the troubleshooting procedures for coolant sensor and maf here in the factory service manual - it's for a 2002 even though it says 96 in the link. :cheers:

1996 to 2002 Toyota 4Runner OEM Repair and Wiring Manuals
 
Joined
Nov 14, 2007
Messages
34
Location
Grants Pass
Luke Zero,
Thanks for the brake advice, Advance Auto doesn't seem to have the Bendix rotors in right now, so I think I'll search out a USA made equivalent somewhere.

raydouble,

That FSM link is righteous! Thanks, yet again. I was staring at the pages that have pictures of the MAF Sensor and noticed that I didn't recognize the two platinum wires from when I "cleaned" mine before. This got me thinking, so I looked up the cleaning process again and found this link: Toyota 4Runner Highlander Mass Air Flow Sensor MAF cleaning
I'd suggest replacing the linked guide you have in the 3rd Gen FAQs page with this one as it was what I was able to understand better (I'm by no means a mechanic so I could have just read the first one wrong, but isn't that kinda the point of the guide?).

So far with the MAF Sensor truly clean I've got no new CEL light problems and she's running smooth! (knock on wood!) On to the Brakes, fluid changes, and so on and so on...

I really appreciate the help guys!

RH01

oh and raydouble... The Dude Abides.
 
Joined
Nov 14, 2007
Messages
34
Location
Grants Pass
Off Thread Topic Brake update

Found a set of Brembo brake rotors (P/N BR25488) on the cheap at www.discountbrakes.com the total for both rotors and shipping was $112.18. Looked around for about 10 seconds to find this was the best price I could get on Brembo rotors. Hopefully I'm right. Thanks again.

RH01
 

apeterson

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Jul 20, 2006
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Pequot Lakes MN
I had non stop problems with my rotors and pads..... changed to all toyota parts and problem fixed... have done 2 98 4runners (mine and a friends) both with no problems.
 

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