User Tag List

Reply
 
Thread Tools Rate Thread Display Modes
Old 06-27-2020, 10:32 AM #1
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
P0172 Bank 1 Running Rich

Help, my 2007 4Runner V8 just threw a P0172 code and there doesn't seem to be much info associated with this code on the forum for 4th gens. Does anyone have any ideas where to start? I'm going to try cleaning the MAF and see what happens... other ideas? The 02 sensor is $164, which seems a little pricey to just replace on a wim. Other thoughts? Thank you!
cice is offline   Reply With QuoteReply With Quote
Old 06-27-2020, 02:28 PM #2
Jpilot Jpilot is offline
Member
 
Join Date: Nov 2019
Location: Lafayette, Co
Posts: 194
Real Name: Joe
Jpilot will become famous soon enough Jpilot will become famous soon enough
Jpilot Jpilot is offline
Member
 
Join Date: Nov 2019
Location: Lafayette, Co
Posts: 194
Real Name: Joe
Jpilot will become famous soon enough Jpilot will become famous soon enough
Checks

Quote:
Originally Posted by cice View Post
Help, my 2007 4Runner V8 just threw a P0172 code and there doesn't seem to be much info associated with this code on the forum for 4th gens. Does anyone have any ideas where to start? I'm going to try cleaning the MAF and see what happens... other ideas? The 02 sensor is $164, which seems a little pricey to just replace on a wim. Other thoughts? Thank you!
Some things to check:
Clean the MAF first, make sure you use MAF cleaner, not Carb cleaner
Engine coolant sensor
Airbox connection, if there is a leak and excess air is getting in to the MAF sensor
Clean Air filter


Best of luck, let us know how it goes.
__________________
2015 T4R Trail Red, 3” lift, 285s, Niserack, HF rock sliders, BA bumper
2006 4runner sport, v6, Tacoma TRD springs front, airbags And 2” spacers in rear. 440k and still chuggin along.
1977 FJ40, V8, lifted, Warn 8274 winch etc.
2006 GX470, 285s, 2” lift, C4lo sliders
Jpilot is offline   Reply With QuoteReply With Quote
Old 06-27-2020, 06:43 PM #3
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
Thanks, I cleaned the MAF (with MAF cleaner) and the CEL went away and hasn't come on again after ~175 miles of driving today!
cice is offline   Reply With QuoteReply With Quote
Old 06-27-2020, 07:28 PM #4
importman importman is offline
Member
 
Join Date: Feb 2020
Location: Lake City,SC
Posts: 486
Real Name: Danny
importman is a jewel in the rough importman is a jewel in the rough importman is a jewel in the rough importman is a jewel in the rough
importman importman is offline
Member
 
Join Date: Feb 2020
Location: Lake City,SC
Posts: 486
Real Name: Danny
importman is a jewel in the rough importman is a jewel in the rough importman is a jewel in the rough importman is a jewel in the rough
It will probably come on again. A dirty MAF sensor will typically cause a lean code rather than a rich one. If you had a rich code on one bank I would suspect you have one or more leaky injectors. For your sake I hope it's fixed but I just wouldn't count on it.
importman is offline   Reply With QuoteReply With Quote
Old 07-09-2020, 10:26 AM #5
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
Well you were right, after two weeks it has come back on. Now it is throwing P0172 (bank 1 too rich) and P0175 (bank 2 too rich). Should I replace the MAF since cleaning it made the original P0172 code go away? Maybe replace the 02 sensors (are there one or two for the V8)?

If it is an injector (or multiple injectors) how do I test this? Thank you!
cice is offline   Reply With QuoteReply With Quote
Old 07-09-2020, 07:18 PM #6
importman importman is offline
Member
 
Join Date: Feb 2020
Location: Lake City,SC
Posts: 486
Real Name: Danny
importman is a jewel in the rough importman is a jewel in the rough importman is a jewel in the rough importman is a jewel in the rough
importman importman is offline
Member
 
Join Date: Feb 2020
Location: Lake City,SC
Posts: 486
Real Name: Danny
importman is a jewel in the rough importman is a jewel in the rough importman is a jewel in the rough importman is a jewel in the rough
One way would be to connect a fuel pressure gauge to the fuel system and pressurize it by turning the key on. Then turn the key off and watch the gauge. The pressure should hold fairly steady for a little while, (sorry I don't remember how long exactly). But if it bleeds off pressure in say 15-30 minutes, you likely have an injector leaking. You might also be able to tell by pulling the plugs and looking for any that are wet with gas or really black. Hope this helps some.
importman is offline   Reply With QuoteReply With Quote
Old 07-09-2020, 09:48 PM #7
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
Good ideas, the spark plugs are a very good place to start. Thank you!

I cleaned the MAF and the CEL went away all on its own after a little driving. I've ordered a new Hitachi MAF, which I think is OEM as the MAF in my vehicle says Hitachi on it. I'm also going to replace the two upstream o2 sensors as well. Hopefully with these are the cause of the problem. If not, I'll be pulling the plugs and also doing the pressure test.
cice is offline   Reply With QuoteReply With Quote
Old 07-14-2020, 11:39 AM #8
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
Well, I replaced the MAF and the two upstream O2 sensors on my 2007 4.7L V8. The code is gone... for now.
cice is offline   Reply With QuoteReply With Quote
Old 08-12-2020, 10:37 PM #9
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
cice cice is offline
Member
 
Join Date: Jan 2012
Posts: 61
cice is on a distinguished road
After about three weeks of driving the P0172 and P0175 codes came back. I wasn't brave enough to attempt the fuel pressure check, so I took it to a shop. They cleaned the throttle body and the codes went away. After checking the fuel pressure, driving it with their monitoring computer attached, they finally decided there is nothing else wrong. So for anyone still following or who finds this thread, try cleaning the throttle body also. Hopefully this is the end of the rich codes saga for my 4Runner.
cice is offline   Reply With QuoteReply With Quote
Old 11-14-2020, 10:29 PM #10
BoostinZX's Avatar
BoostinZX BoostinZX is offline
Member
 
Join Date: Aug 2012
Location: East, TN
Posts: 70
BoostinZX is on a distinguished road
BoostinZX BoostinZX is offline
Member
BoostinZX's Avatar
 
Join Date: Aug 2012
Location: East, TN
Posts: 70
BoostinZX is on a distinguished road
Keep us posted. I’ve had the same issue off and on for going on 3 years. Everything I’ve swapped has “fixed” it but they come back unfortunately.
__________________
2005 Limited V8 4x4
BoostinZX is offline   Reply With QuoteReply With Quote
Reply

Tags
code , ideas , p0172 , start , thoughts

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
3rz running rich cantaloop 3rd gen T4Rs 2 07-02-2017 05:51 PM
Running rich at WOT? BoatRacer Classic T4Rs 0 03-02-2015 11:21 PM
Running Rich??? sixonthefloor Classic T4Rs 5 03-12-2008 06:18 AM
help Bank 1 is too rich 99cruisin 3rd gen T4Rs 3 09-10-2006 04:14 PM
running rich imboredeveryday 3rd gen T4Rs 5 08-17-2006 11:32 PM

Powered by vBadvanced CMPS v3.2.2

All times are GMT -4. The time now is 05:06 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.
Feedback Buttons provided by Advanced Post Thanks / Like (Lite) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Lite) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.
***This site is an unofficial Toyota site, and is not officially endorsed, supported, authorized by or affiliated with Toyota. All company, product, or service names references in this web site are used for identification purposes only and may be trademarks of their respective owners. The Toyota name, marks, designs and logos, as well as Toyota model names, are registered trademarks of Toyota Motor Corporation***Ad Management plugin by RedTyger
 
Copyright © 2020