Engine check light: P0171

Nam · 09-13-2004, 10:06 AM

Last labor day weekend, while towing a 16' boat to Fresno from Sacramento, CA, the engine check light came on. I still get 19MHP consistently with full load, three passengers, and towing the boat with camping gears on it.

Went home, checked out the code, it said P0171, system too lean (sp), I reset the ECU, for two days, the light hasn't come back on.

What could be the problem? any help is highly appreciated. Is it related to the MAF sensor? I hear that thing is very expensive.

I have 77K miles on the truck.

Thanks,

Nam

This ad is not displayed to registered members.
Register your free account today and become a member on Yotatech!

lee · 09-13-2004, 10:44 AM

it is indeed the MAF. you can clean it yourself and not get a whole new one.

or if you have a warranty/extended warranty, you can get it done free at the stealership.

Rick F. · 09-13-2004, 12:14 PM

I didn't check, but if P0171 is the MAF, there ae plenty of write-ups in the tech section that you can use to do-it-yourself. If I have time, I (or someone else on the forum) will confirm the the code.

Nam · 09-13-2004, 12:48 PM

Thanks Lee & Rick. I'll do the search.

Nam

lee · 09-13-2004, 12:49 PM

thats the code i got when it was my MAF.

4-RUNNIN' FREAK · 09-13-2004, 12:57 PM

I got system too lean (bank 1) for P0171

lee · 09-13-2004, 05:10 PM

which is caused by a dirty MAF in that instance... as far as i know

Nam · 09-13-2004, 05:55 PM

Thanks every one for your promptly replies. I've just finished cleaning the MAF sensor. It turns out to be a 10 min. job. I had to temporary relocated the cruise control module to gain better access...but very simple, quick, and easy!

Prior to this, I stopped by Lowes to pick up an "electrical connector cleaner" can, the sensor looks *very* dirty especially from the outer side (facing the airbox). Wish I had the camera handy so I could take some pics. Oh well...it's done.

Hopefully this will solve the supposed-to-be-costly problem.

Nam

Pretacopower · 09-13-2004, 06:35 PM

Yeah I got the same code at 75,000 miles after playing in some dirt one day. Unfortunatley, I had mine cleaned and it still didn't work. Had to replace it

Luckily though, the extended warranty covered it. I remember reading here somewhere that someone's dealer wouldn't cover MAF's under the extended warranty, but mine did

Oh well I won't complain

lee · 09-14-2004, 05:07 AM

you might be thinking of my thread, where i told them i had the warranty when i brought it in, they still charged me over 300 bucks. then i went back in after finding out it was supposed to be warrantied work.

dont worry, i got it all back.

MTL_4runner · 09-14-2004, 05:08 AM

9 times out of 10 it is indeed the MAF causing that code...
If cleaning doesn't do the trick then it will need to be replaced (check junkyards too for parts)

Nam · 09-14-2004, 08:00 AM

Pretacopower:: how much did it cost you for the sensor?

Lee:: lucky you...mine is out of warranty for a long time; however, I hope the cleaning trick will do it.

MTL_4runner:: Thanks for the info. I like your OBD II scan tool. I use the generic one which could only tell me the codes.

Nam

Pretacopower · 09-14-2004, 11:20 AM

Quote:

Originally Posted by Nam

Pretacopower:: how much did it cost you for the sensor?

Nam

Mine was covered under warranty, but I remember my local mechanic said it would cost me $250 installed (or somewhere around there).

DavidA · 09-14-2004, 03:26 PM

I got a used one for $150 from a junk yard. Worked great after I screwed the first one up.

IS3004Runner · 09-17-2004, 12:40 PM

Quote:

Originally Posted by DavidA

I got a used one for $150 from a junk yard. Worked great after I screwed the first one up.

i just got mine too at a junk yard for $75. It came from a 2002 camry. they sell it at the dealer for $151 brand new. FYI, our MAF is the same as 98-03 sienna, 2002-04 camry, 2001-2 highlander, and the 1st gen RX300.

Nam · 10-07-2004, 07:09 AM

Update!!!

After cleaning the MAF sensor, about two weeks later, the engine check light is back on...it went off for a day and came back on again. Checked out the code, it said P0171 again.

Time for a new sensor I guess!

IS3004Runner: thanks for the infor. if that is the case, I will try to swap mine with my dad's 2000 Sienna and see if it is going to solve the problem.

any other suggestions?

Nam

MTL_4runner · 10-07-2004, 10:26 AM

Quote:

Originally Posted by Nam

Update!!!

After cleaning the MAF sensor, about two weeks later, the engine check light is back on...it went off for a day and came back on again. Checked out the code, it said P0171 again.

Time for a new sensor I guess!

IS3004Runner: thanks for the infor. if that is the case, I will try to swap mine with my dad's 2000 Sienna and see if it is going to solve the problem.

any other suggestions?

Nam

Nope, you definately need a new sensor....
Many have had good luck with getting a used one out of the junkyard too.

Unhappy99 · 10-07-2004, 11:56 AM

Did you actually clean both hotwires, or just the obvious bulby thingy? With what cleaner?

Nam · 10-07-2004, 12:04 PM

Quote:

Originally Posted by Unhappy99

Did you actually clean both hotwires, or just the obvious bulby thingy? With what cleaner?

No wires...I just cleaned the bulby thing with "Electrical Contact Cleaner" and couples of Q-tips.

One even that kind of noticable to me was that I flood the engine with water since the door lach of the air filter was open and I went through water without knowing it...it stalled the engine for a moment and it started right up. The air filter was soaked with water...

I am not sure if that would make the MAF sensor dirty or malfunction...I'll double check and see.

Last result, get a new sensor...thanks to Montreal_4Runner

Nam

Nam · 10-07-2004, 12:05 PM

Quote:

Originally Posted by MTL_4runner

Nope, you definately need a new sensor....
Many have had good luck with getting a used one out of the junkyard too.

I will check local junk yard and see what they have. I don't think it's too hard to find.

Thanks,

Nam

09-13-2004, 12:14 PM	#3 (permalink)
Rick F. Registered User Personal Sales Rating: (0) Join Date: Nov 2002 Location: Far western Kentucky (transplanted from central PA) Posts: 1,066	I didn't check, but if P0171 is the MAF, there ae plenty of write-ups in the tech section that you can use to do-it-yourself. If I have time, I (or someone else on the forum) will confirm the the code. __________________ '00 SR5, Desert Dune: 4" Deckplate, Amsoil TS-115, Bilsteins, Brembo rotors w/Performance Friction pads, Fiam Highway Blasters, Sylvania Silverstars, Hella Micro DE Fog Lights w/Hella Yellow Star Lamps - SOLD 1/24/09 '08 Sport, Salsa Red: Hella Optilux fogs, Silverstar Ultra Hi beams. Pending: Borla dual catback, CAI, shocks

09-13-2004, 12:48 PM	#4 (permalink)
Nam Registered User Personal Sales Rating: (0) [OP] Join Date: Jul 2003 Location: Sacramento, Calif. Posts: 142	Thanks Lee & Rick. I'll do the search. Nam __________________ 2000 4Runner Metalic Silver LTD 4WD!

09-13-2004, 12:57 PM	#6 (permalink)
4-RUNNIN' FREAK Contributing Member Personal Sales Rating: (0) Join Date: Jun 2004 Location: NNJ Posts: 3,950	I got system too lean (bank 1) for P0171 __________________ '02 4Runner - '06 XRunner www.BadgeYourRide.com Check this out Multi-Touch Interaction Research http://mrl.nyu.edu/~jhan/ftirtouch/ Still A Neon

09-13-2004, 05:55 PM	#8 (permalink)
Nam Registered User Personal Sales Rating: (0) [OP] Join Date: Jul 2003 Location: Sacramento, Calif. Posts: 142	Thanks every one for your promptly replies. I've just finished cleaning the MAF sensor. It turns out to be a 10 min. job. I had to temporary relocated the cruise control module to gain better access...but very simple, quick, and easy! Prior to this, I stopped by Lowes to pick up an "electrical connector cleaner" can, the sensor looks very dirty especially from the outer side (facing the airbox). Wish I had the camera handy so I could take some pics. Oh well...it's done. Hopefully this will solve the supposed-to-be-costly problem. Nam __________________ 2000 4Runner Metalic Silver LTD 4WD!

09-13-2004, 06:35 PM	#9 (permalink)
Pretacopower Contributing Member Personal Sales Rating: (0) Join Date: Oct 2003 Location: Santa Clarita, CA Posts: 1,013	Yeah I got the same code at 75,000 miles after playing in some dirt one day. Unfortunatley, I had mine cleaned and it still didn't work. Had to replace it Luckily though, the extended warranty covered it. I remember reading here somewhere that someone's dealer wouldn't cover MAF's under the extended warranty, but mine did Oh well I won't complain __________________ ---Ryan--- 1999 V6 2WD (locked) Tacoma Prerunner

09-13-2004, 10:44 AM	#2 (permalink)
lee Contributing Member Personal Sales Rating: (0) Join Date: Dec 2003 Location: boston, ma Posts: 6,731	it is indeed the MAF. you can clean it yourself and not get a whole new one. or if you have a warranty/extended warranty, you can get it done free at the stealership.

09-13-2004, 12:49 PM	#5 (permalink)
lee Contributing Member Personal Sales Rating: (0) Join Date: Dec 2003 Location: boston, ma Posts: 6,731	thats the code i got when it was my MAF.

09-13-2004, 05:10 PM	#7 (permalink)
lee Contributing Member Personal Sales Rating: (0) Join Date: Dec 2003 Location: boston, ma Posts: 6,731	which is caused by a dirty MAF in that instance... as far as i know

09-14-2004, 05:07 AM	#10 (permalink)
lee Contributing Member Personal Sales Rating: (0) Join Date: Dec 2003 Location: boston, ma Posts: 6,731	you might be thinking of my thread, where i told them i had the warranty when i brought it in, they still charged me over 300 bucks. then i went back in after finding out it was supposed to be warrantied work. dont worry, i got it all back.

09-14-2004, 05:08 AM	#11 (permalink)
MTL_4runner Contributing Member Personal Sales Rating: (0) Join Date: Jul 2003 Location: Montreal, QC Canada Posts: 8,807	9 times out of 10 it is indeed the MAF causing that code... If cleaning doesn't do the trick then it will need to be replaced (check junkyards too for parts) __________________ - Jamie 1996 4Runner SR5 4X4 Auto Deckplate Mod, Hayden Tranny Cooler, Amsoil Air Filter, OME 881/906 N86C/N91SC Lift Best OBD II scan tool I have used!. .....and I am AMERICAN!

09-14-2004, 08:00 AM	#12 (permalink)
Nam Registered User Personal Sales Rating: (0) [OP] Join Date: Jul 2003 Location: Sacramento, Calif. Posts: 142	Pretacopower:: how much did it cost you for the sensor? Lee:: lucky you...mine is out of warranty for a long time; however, I hope the cleaning trick will do it. MTL_4runner:: Thanks for the info. I like your OBD II scan tool. I use the generic one which could only tell me the codes. Nam __________________ 2000 4Runner Metalic Silver LTD 4WD!

09-14-2004, 03:26 PM	#14 (permalink)
DavidA Contributing Member Personal Sales Rating: (0) Join Date: Apr 2004 Location: Fort Worth, TX Posts: 919	I got a used one for $150 from a junk yard. Worked great after I screwed the first one up. __________________ 2002 Stellar Blue 4Runner Sport Edition Cold Air Intake Magnaflow Exhaust Iridium Sparkplugs Kenwood KDC-MP628 Blaupunkt Separates in all of the doors Two RF P2002 amps Kenwood 12" Subwoofer My baby: Pics

10-07-2004, 07:09 AM	#16 (permalink)
Nam Registered User Personal Sales Rating: (0) [OP] Join Date: Jul 2003 Location: Sacramento, Calif. Posts: 142	Update!!! After cleaning the MAF sensor, about two weeks later, the engine check light is back on...it went off for a day and came back on again. Checked out the code, it said P0171 again. Time for a new sensor I guess! IS3004Runner: thanks for the infor. if that is the case, I will try to swap mine with my dad's 2000 Sienna and see if it is going to solve the problem. any other suggestions? Nam __________________ 2000 4Runner Metalic Silver LTD 4WD!

10-07-2004, 11:56 AM	#18 (permalink)
Unhappy99 Registered User Personal Sales Rating: (0) Join Date: Sep 2003 Location: Albuquerque, NM Posts: 380	Did you actually clean both hotwires, or just the obvious bulby thingy? With what cleaner? __________________ 03 Dodge Ram 2500 CTD...its amazing Ex: 1999 4Runner JT3HN86R1X0199261...Now somebody elses Karl Malone Toyota 'Certified' POS Legendary Toyota quality is exactly that: A thing of legend. Defective fuel gauge - 'Certified' Defective brake rotors - 'Certified' Defective axle seals - 'Certified' Defective heater diverter - 'Certified' etc. etc. etc.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Check engine light	poolman	86-95 Trucks & 4Runners	5	01-22-2007 08:48 PM
Engine swap/check engine light?	spacoli	86-95 Trucks & 4Runners	1	11-29-2006 06:39 PM
Engine Miss/Check engine light - Possibly TPS?	Extremesolo	95.5-2004 Tacomas & 96-2002 4Runners	2	09-17-2005 08:58 PM
check engine light + engine miss	descendents	95.5-2004 Tacomas & 96-2002 4Runners	6	11-03-2003 06:51 PM