Toyota

Have Toyota Questions? Ask a Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

on a 2001 toyota celica gt, i got CEL PO171, when i changed…

Customer Question
on a 2001 toyota celica...
on a 2001 toyota celica gt, i got CEL PO171, when i changed the air filter it was almost blackish, and when i ran a light test, no light passed through it. i changed that air filter, and then cel was still on, i did a full tune up, changed sparks plugs to OEM NGK Iridium, then i cleaned the Mass Air Flow sensor...with MAF sensor cleaner from autozone....that didn't work...i kept resetting cel each time, came back on within 2-15 miles of driving each time. listened for a vacumm leak and heard nothing...(not 100% sure...)...maybe change the fuel filter? or fuel pump? any ideas?
Submitted: 5 years ago.Category: Toyota
Show More
Show Less
Ask Your Own Toyota Question
Answered in 6 hours by:
5/25/2013
Toyota Mechanic: Matt, Mechanical Engineer replied 5 years ago
Matt
Matt, Mechanical Engineer
Category: Toyota
Satisfied Customers: 23,206
Experience: BEng, Repaired my own cars and others for 20 years, worked in Formula 1 for 10 years
Verified

Hello

Check for exhaust leaks before the O2 sensor as if this has been experiencing an exhaust leak then it will have been running very rich as the sensor will see the extra air pulled in as fresh / lean fuelling and be adding fuel to compensate.

this can lead to catalyst failure as the extra fuel can re-light inside and melt the catalyst

The best way to find an exhaust leak is to run the engine from cold and feel around the exhaust joints with your bare hands - you'll have about 30 seconds before it all gets too hot and you should feel any escaping gas blowing over your fingers

I'd also check for air leaks the best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane around each joint in turn. If the engine rev's up you've found your leak.
Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements.

 

Also replace the spark plugs if any of them fail this checklist:

http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

Ask Your Own Toyota Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a toyota mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Matt Your Own Question
Matt
Matt
Matt, Mechanical Engineer
Category: Toyota
Satisfied Customers: 23,206
23,206 Satisfied Customers
Experience: BEng, Repaired my own cars and others for 20 years, worked in Formula 1 for 10 years

Matt is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

THANK YOU, THANK YOU, THANK YOU!! I've got my baby back. Tomorrow I will get a tank of high octane, remove the top, go for a long long ride and enjoy my car. THANK YOU!

JugheadUSA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

Chris (aka-Moose)

Chris (aka-Moose)

Auto Technician

1,104 satisfied customers

16 years of experience

Marty

Marty

ASE Certified Technician

197 satisfied customers

ASE & Bosch Master Tech. 30 years experience.

Amedee

Amedee

Toyota Technician

1,243 satisfied customers

ASE certified tech advanced level specialist. Wisconsin certified emissions state inspector

Anthony

Anthony

ASE Certified Technician

401 satisfied customers

ASE Master Automobile Technician with over 20 years exp. in this field.

Richard

Richard

ASE Certified Technician

9 satisfied customers

Toyota tech. ASE Certified Technician

Skyvisions

Skyvisions

ASE Certified Technician

13,051 satisfied customers

Toyota Master Diagnostic

Genchi Genbutsu

Genchi Genbutsu

Toyota Master Technician

3,761 satisfied customers

Toyota Certified Master Diagnostic Technician, ASE Master Technician with L1 Advanced Engine

< Previous | Next >

Related Toyota Questions
I installed new air filters, told that would give me better
I installed new air filters, told that would give me better milage. Check engine lite randomly going on and off. MPG has gone from 45mi down to 27mi. 2005 Toyota 2005, Prius. It runs well and I am loo… read more
ted ritter
ted ritter
Team Leader/toyota master tech/retired
High School or GED
2,692 satisfied customers
Bad pulley on tensioner. 2000 celica GTS. Looks like i need
yes looks like i need a spacial wrench for the bolt. … read more
Chris (aka-Moose)
Chris (aka-Moose)
Auto Technician
Vocational, Technical or Trade School
1,104 satisfied customers
I have a 1988 Toyota Celica GT. I can not locate the starter
I have a 1988 Toyota Celica GT. I can not locate the starter relay switch, where should I look and replace? … read more
ted ritter
ted ritter
Team Leader/toyota master tech/retired
High School or GED
2,692 satisfied customers
2000 Celica GT, 1ZZFE ENGINE: 86K ON ENGINE, AUTO. I am a
I am a former professional mechanic, but am running out of ideas. PO171, PO300, lean running, stumble at idle, excellent compression 205 psi-212 psi on all cylinders … read more
Matt
Matt
Mechanical Engineer
23,206 satisfied customers
What is the torque setting for the spark plugs on a 2012
What is the torque setting for the spark plugs on a 2012 Toyota Camry .. 2.5 liter 4 cylinder?… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
It cranks but will not start. It has fuel the spark plugs
when i plugged the diagnostics tool it ran a code of p0174 2006 solara … read more
Jared D
Jared D
Shop Supervisor
Bachelor\u0027s
3 satisfied customers
Where is the back up lamp switch on a 1993 Celica GT
Where is the back up lamp switch on a 1993 Celica GT convertible with automatic … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
5,494 satisfied customers
I have a 2000 toyota celica gt. The only way the car will
I have a 2000 toyota celica gt. The only way the car will run is with either the mass air flow sensor disconnected, or the green wire to the maf sensor being disconnected while the mass air flow senso… read more
ted ritter
ted ritter
Team Leader/toyota master tech/retired
High School or GED
2,692 satisfied customers
I have replaced the battery in my 2000 Celica gts and the
I have replaced the battery in my 2000 Celica gts and the immobilizer will not let me start my car … read more
TIM MOHR
TIM MOHR
SHOP OWNER
Master's Degree
8,037 satisfied customers
2002 celica gt. Won't start, good battery but no sounds or
2002 celica gt. Won't start, good battery but no sounds or chimes when cranking or dash lights when attempting to start. Played with buttons on alarm remote and started but not again. Alarm keeps goin… read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
5,323 satisfied customers
My 2001 celica gt,steering wheel started shaking, and now
hi, my 2001 celica gt,steering wheel started shaking, and now its making a noise when i take off,like a binding or sweeling noise ,in the front end-not the motor ,please help. … read more
Toyota Service
Toyota Service
Toyota Dealership Service & CR Manager
1,344 satisfied customers
1994 Celica GT. Accessory Belt that drives the A/C pump and
1994 Celica GT. Accessory Belt that drives the A/C pump and alternator suddenly loosened and I can't tell why. A new one from the parts store does not fit either. I don't see any missing parts and the… read more
HDGENE
HDGENE
Master Technician/Lead Technician
Associate Degree
2,835 satisfied customers
Need some electrical problem help. 2001 Toyota celica gts. I
Yes, I checked all fuses under the hood and interior, checked all relays. I did a voltage drop test which I got a 0.01, checked the battery and alternator and still none of my dash lights,windows, radio and moon roof work … read more
ted ritter
ted ritter
Team Leader/toyota master tech/retired
High School or GED
2,692 satisfied customers
Just change my sparks plug and air filter car still keeps
Just change my sparks plug and air filter car still keeps cutting off … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
I have a 2000 Celica GT and getting code po340, camshaft
I have a 2000 Celica GT and getting code po340, camshaft position sensor … read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
5,323 satisfied customers
I have a 2003 celica gt...the check engine light went on and
i have a 2003 celica gt...the check engine light went on and know it keeps boging out … read more
Peter Bagley
Peter Bagley
master technition
Vocational, Technical or Trade School
1,240 satisfied customers
The check engine comes on with the air filter in place. But
the check engine comes on with the air filter in place. But when I remove the air filter the check engine light comes on? Why ? … read more
sprinkles08
sprinkles08
Technician
High School or GED
11 satisfied customers
2002 toyota celica gt getting code p0171 replaced air filter
2002 toyota celica gt getting code p0171 replaced air filter cleaned maf sensor checked maf sensor ny unplugging it and it seems to worl as vehicle turned off once i did that. I dont see any vacuum le… read more
Chris (aka-Moose)
Chris (aka-Moose)
Auto Technician
Vocational, Technical or Trade School
1,104 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x