05-24-2021, 08:19 PM
|
#1
|
Member
|
|
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
|
Member
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
Check Engine Light + Codes After MAF/Throttle Body Clean
Hi All
Feel sick to my stomach after I undertook the cleaning of the MAF and throttle body on our new to us ‘99 4Runner.
I removed and reconnected what I think is everything but after about 15 minutes got a check Engine light after turning the ignition back on after stopping.
I figured maybe the ecu need a reset so I pulled the negative terminal and EFI fuse. The check engine light stayed off even after a very rough idle (which I assume is idle relearning after the efi fuse pull) and then came back again after 20 minutes of driving. Engine light seemed to come back again after an acceleration?
There is nothing noticeably weird going on, and power seems just fine, but i do need to get this solved.
Current codes are:
P0015
P0123
P0301
P1693
I’m really hoping this is a connection issue which i will go back through - but is there a logical place to start here?
Thanks for any help here.
__________________
'99 4Runner Limited White/Silver
|
|
Reply With Quote
|
05-24-2021, 08:31 PM
|
#2
|
|
Senior Member
|
|
Join Date: Apr 2020
Location: Monroe, WA
Posts: 2,197
Real Name: Devan
|
|
Senior Member
Join Date: Apr 2020
Location: Monroe, WA
Posts: 2,197
Real Name: Devan
|
Just a crazy, wild guess; did you mix up the IAC's vacuum and coolant line? Assuming the throttle body was taken off the engine.
Would explain the misfire code and why it happens more so on acceleration.
__________________
Y2K Highlander Millennium Silver 3.4L auto @ 320k and climbing
Toytecs + 5100s / 7.5 wrap + OME spacers + Tokicos / JBA UCAs / Anonymous Fab. LBJs / Total Chaos Gussets / EimKeith PCK + LCAR / Extended Bump Stops; Brake Lines; Rear Diff Breather / True North Fab. Hybrid Bumper / CBI Hybrid Bumper + Tire Carrier / 4xInnovations Hybrid Sliders / Opt Offroad Trailing Arms / Lil Skip Gas Skid / BudBuilt Front Skid / ARB Rear Locker
Last edited by Devbot; 05-24-2021 at 08:34 PM.
|
|
Reply With Quote
|
05-24-2021, 08:41 PM
|
#3
|
Member
|
|
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
|
Member
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
Thanks - will definitely check that.
__________________
'99 4Runner Limited White/Silver
|
|
Reply With Quote
|
05-24-2021, 08:45 PM
|
#4
|
Member
|
|
Join Date: Nov 2018
Location: San Jose, CA
Posts: 522
|
|
Member
Join Date: Nov 2018
Location: San Jose, CA
Posts: 522
|
Did you pull the codes before you disconnected the battery or after? If before, did they all come back after or only some of them?
|
|
Reply With Quote
|
05-24-2021, 10:17 PM
|
#5
|
Member
|
|
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
|
Member
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
I will try again, 3 of them had definitely come back after the reset. The fourth appears new
__________________
'99 4Runner Limited White/Silver
|
|
Reply With Quote
|
05-24-2021, 10:55 PM
|
#6
|
Member
|
|
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
|
Member
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
Ok so I retested with OBD fusion and am only getting a single code now which is P0171. This is with the key in the on position, but ignition off.
__________________
'99 4Runner Limited White/Silver
|
|
Reply With Quote
|
05-24-2021, 11:01 PM
|
#7
|
|
Senior Member
|
|
Join Date: Apr 2020
Location: Monroe, WA
Posts: 2,197
Real Name: Devan
|
|
Senior Member
Join Date: Apr 2020
Location: Monroe, WA
Posts: 2,197
Real Name: Devan
|
P0171 is typically a dirty MAF. When you cleaned it, did you let it air dry for a bit or did you spray it and toss it right in? Sometimes when people don't wait for it to dry completely it supposedly likes to trip out for a little while. I've personally always doubted this because MAF cleaner evaporates immediately, but it's definitely something I've seen said more than once so perhaps theres truth to it.
__________________
Y2K Highlander Millennium Silver 3.4L auto @ 320k and climbing
Toytecs + 5100s / 7.5 wrap + OME spacers + Tokicos / JBA UCAs / Anonymous Fab. LBJs / Total Chaos Gussets / EimKeith PCK + LCAR / Extended Bump Stops; Brake Lines; Rear Diff Breather / True North Fab. Hybrid Bumper / CBI Hybrid Bumper + Tire Carrier / 4xInnovations Hybrid Sliders / Opt Offroad Trailing Arms / Lil Skip Gas Skid / BudBuilt Front Skid / ARB Rear Locker
|
|
Reply With Quote
|
05-25-2021, 12:01 AM
|
#8
|
|
Senior Member
|
|
Join Date: Mar 2010
Location: denver
Posts: 3,010
|
|
Senior Member
Join Date: Mar 2010
Location: denver
Posts: 3,010
|
Check for vacuum leaks cracked hoses etc also.
|
|
Reply With Quote
|
05-25-2021, 12:51 AM
|
#9
|
Member
|
|
Join Date: Nov 2018
Location: San Jose, CA
Posts: 522
|
|
Member
Join Date: Nov 2018
Location: San Jose, CA
Posts: 522
|
Per the FSM, these are the possible causes of the P0171 (System too lean):
Air induction system
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
Fuel pressure
Gas leakage on exhaust system
Open or short in A/F sensor (bank 1 sensor 1) circuit
A/F sensor (bank 1 sensor 1)
ECM
Given the work you just did, I'd focus on looking for a vacuum leak as has already been suggested as the most likely cause followed by an issue with the MAF. The rest of the list are unrelated the the work you did, so they would be coincidental problems rather than caused by the work you just did.
|
|
Reply With Quote
|
05-25-2021, 10:46 AM
|
#10
|
Member
|
|
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
|
Member
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
Quote:
Originally Posted by Skulking
Per the FSM, these are the possible causes of the P0171 (System too lean):
Air induction system
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
Fuel pressure
Gas leakage on exhaust system
Open or short in A/F sensor (bank 1 sensor 1) circuit
A/F sensor (bank 1 sensor 1)
ECM
Given the work you just did, I'd focus on looking for a vacuum leak as has already been suggested as the most likely cause followed by an issue with the MAF. The rest of the list are unrelated the the work you did, so they would be coincidental problems rather than caused by the work you just did.
|
Thanks I have tried pushing all the vacuum hoses firm against the fittings and taped the cracks at the ends on some of the small ones.
Took out and cleaned the MAF again and cleared code. Code stayed off for a quick 10 minute drive this morning, but it may not have been long enough. Will test again.
I guess there is a potential that I could have damaged the MAF during the cleaning, touching with the straw or something.
__________________
'99 4Runner Limited White/Silver
|
|
Reply With Quote
|
05-25-2021, 12:05 PM
|
#11
|
|
Senior Member
|
|
Join Date: Mar 2010
Location: denver
Posts: 3,010
|
|
Senior Member
Join Date: Mar 2010
Location: denver
Posts: 3,010
|
Quote:
Originally Posted by rocky.mtn
Thanks I have tried pushing all the vacuum hoses firm against the fittings and taped the cracks at the ends on some of the small ones.
Took out and cleaned the MAF again and cleared code. Code stayed off for a quick 10 minute drive this morning, but it may not have been long enough. Will test again.
I guess there is a potential that I could have damaged the MAF during the cleaning, touching with the straw or something.
|
If'yours is damaged this is a good price for a used densone. clean it before'you put it in but 20 bucks is a good risk.
https://rover.ebay.com/rover/0/0/0?m...2F383615150827
|
|
Reply With Quote
|
05-25-2021, 04:01 PM
|
#12
|
Member
|
|
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
|
Member
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
So I re-ran at lunch and the P071 returned. Seems it is always returning on the second trip after clearing it with OBD Fusion.
I did take some readings:
Warm Idle 597 RPM @ 191 F Engine Temp
MAF 0.37 lb/min @ Idle
Fuel % Trim Bank 1 - 19.5%
I'm guessing the MAF is too low and fuel % is too high? Even though idle RPMs appear normal.
Struggling to figure out how to nail down if this is a MAF or Vaccuum issue now. I may just buy a new MAF (even though they are darn expensive in Canada) and then re-dig around vaccum lines tonight.
__________________
'99 4Runner Limited White/Silver
Last edited by rocky.mtn; 05-25-2021 at 04:08 PM.
|
|
Reply With Quote
|
05-25-2021, 04:55 PM
|
#13
|
Member
|
|
Join Date: Nov 2018
Location: San Jose, CA
Posts: 522
|
|
Member
Join Date: Nov 2018
Location: San Jose, CA
Posts: 522
|
Quote:
Originally Posted by rocky.mtn
So I re-ran at lunch and the P071 returned. Seems it is always returning on the second trip after clearing it with OBD Fusion.
I did take some readings:
Warm Idle 597 RPM @ 191 F Engine Temp
MAF 0.37 lb/min @ Idle
Fuel % Trim Bank 1 - 19.5%
I'm guessing the MAF is too low and fuel % is too high? Even though idle RPMs appear normal.
Struggling to figure out how to nail down if this is a MAF or Vaccuum issue now. I may just buy a new MAF (even though they are darn expensive in Canada) and then re-dig around vaccum lines tonight.
|
P0171 has 2 trip detection logic, so after you clear it it shouldn't come back until your second trip.
Converting your MAF reading to g/s I'm getting 2.8g/s. I believe that is within the normal range, but possibly on the low side. Given the fuel trim you are showing it looks like your injectors are dumping as much fuel in as they can to try and get your AFR correct and they can't do it. It's possible that your MAF is reading low and you actually have more air flow than it is measuring, but at this point I'd still be leaning towards vacuum leak.
|
|
Reply With Quote
|
05-25-2021, 05:57 PM
|
#14
|
Senior Member
|
|
Join Date: Feb 2019
Location: Hot Springs, AR
Posts: 4,410
Real Name: Patrick
|
|
Senior Member
Join Date: Feb 2019
Location: Hot Springs, AR
Posts: 4,410
Real Name: Patrick
|
Quote:
Originally Posted by rocky.mtn
So I re-ran at lunch and the P071 returned. Seems it is always returning on the second trip after clearing it with OBD Fusion.
I did take some readings:
Warm Idle 597 RPM @ 191 F Engine Temp
MAF 0.37 lb/min @ Idle
Fuel % Trim Bank 1 - 19.5%
I'm guessing the MAF is too low and fuel % is too high? Even though idle RPMs appear normal.
Struggling to figure out how to nail down if this is a MAF or Vaccuum issue now. I may just buy a new MAF (even though they are darn expensive in Canada) and then re-dig around vaccum lines tonight.
|
To clarify are you showing +19.5% (positive) or -19.5% (negative) fuel trim?
__________________
2000 SR5 V6 Manual 4WD https://www.toyota-4runner.org/3rd-g...biography.html
2000 Limited V6 Auto E-Locker Sold 3/2022
|
|
Reply With Quote
|
05-25-2021, 06:02 PM
|
#15
|
Member
|
|
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
|
Member
Join Date: May 2016
Location: Calgary, Canada
Posts: 98
|
Quote:
Originally Posted by Bad Luck
To clarify are you showing +19.5% (positive) or -19.5% (negative) fuel trim?
|
Thanks.
OBD Fusion isn't showing me a sign notation, so I think it would be positive?
__________________
'99 4Runner Limited White/Silver
|
|
Reply With Quote
|
Thread Tools |
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is On
|
|
|
|