Toyota

Have Toyota Questions? Ask a Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Victor. I have a 98 Camry 4 cyl - someone gave it to me and…

Customer Question
Hi, Victor. I have...
Hi, Victor. I have a 98 Camry 4 cyl - someone gave it to me and I rebuilt the head 2 years ago at which time I also replaced the fuel pump and catalytic converter and both O2 sensors. Since the rebuild it's always had P0171 and P0141 codes turning on the Check Engine light. Last summer it began very hard starting when hot, and now acceleration is poor even in Neutral. Suggestions?
Submitted: 2 years ago.Category: Toyota
Show More
Show Less
Ask Your Own Toyota Question
Answered in 8 minutes by:
1/28/2016
Toyota Mechanic: Joe, ASE Certified Technician replied 2 years ago
Joe
Joe, ASE Certified Technician
Category: Toyota
Satisfied Customers: 7,560
Experience: ASE, electronics, Marine inboards and electronics, automotive drivability, all around repair tech,
Verified

Hello,

Thank you for allowing me to assist you, my name is Joe and I will be happy to assist you with your concern today.

The p0171 is usually going to be a bad o2 sensor relating to the heater circuit, however the p0141 is related to system running too lean: http://www.obd-codes.com/p0171

A code P0171 may mean that one or more of the following has happened: The MAF (Mass Air Flow) Sensor is dirty or faulty Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. There could be a vacuum leak downstream of the MAF sensor Possible cracked vacuum or PCV line/connection Faulty or stuck open PCV valve Failed or faulty oxygen sensor (bank 1, sensor 1) Sticking/plugged or failed fuel injector Low fuel pressure (possible plugged/dirty fuel filter!) Exhaust leak between engine and first oxygen sensor.

I would also check your timing and the valves in the head seeing that the head had work done and could likely be related.

Check fuel pressure as well via a fuel pressure tester and use of professional scan tool will greatly help you with diagnosis as being able to watch systems on the same screen. Checking maf etc.

Thank you!
- Joe

Please rate my answer when ready. Bonuses are appreciated.
If for any reason you are not satisfied please reply back to me for further assistance to which I will be glad to help you. If you have any problems for any reason please reply back and let me know.
Thanks again for using justanswer and have a great day!

If you need any further assistance you can reply back at any time for my help.
I'd be happy to answer any other questions you have even if not related.

Ask Your Own Toyota Question
Customer reply replied 2 years ago
Are the codes possibly switched in your first paragraph? The detailed paragraph for P0171 seems to be dealing with lean mixture. Regarding the O2 sensor heater circuit, since I replaced the sensor, what else would cause the code? Thank you.
Toyota Mechanic: Joe, ASE Certified Technician replied 2 years ago

Correct, my apologies, p0141 is for the heater circuit and the p0171 is related to the lean condition.

O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)

A code P0141 may mean that one or more of the following has happened: open or short to ground in the wiring harness O2 heater circuit wiring high resistance O2 heater element resistance is high Internal short or open in the heater element.

For p0141 make sure the correct sensor was replaced and that the wiring/harness is not at fault.

Thanks,

Joe

Ask Your Own Toyota Question
Customer reply replied 2 years ago
Thank you for your advice on the codes - I hope to put it to use soon as weather allows. The real reason I came to this forum, though, is what I mentioned in the beginning but perhaps did not make clear. Those codes have been present and recurring ever since I got the car but it ran fine for over a year after the head work. Then, during the summer, it got difficult to start when the engine had been running more than a few minutes. Usually I had to let it cool completely down before it would start again. The engine turns over normally. I determined that the spark was fine so I figure it must be fuel, but the maze of emissions controls made me turn to the experts. After a year of that it suddenly developed a new symptom, very poor acceleration even in neutral. It seems to be a bit better when warm, but still not good enough to risk on the roads. Since the codes were there long before those symptoms started I didn't think they were related, although I've replaced the spark plugs, fuel filter, fuel pump, O2 sensors and catalytic converter trying to cure the codes. So, do you have any experience with the hard starting when warm/hot and poor acceleration? Thank you.
Toyota Mechanic: Joe, ASE Certified Technician replied 2 years ago

Codes can be present as soon as a problem starts to occur, the problem can worsen over time until it is actually something noticeable where as in some cases at first it is not, This is why it is so important we as mechanics tell customers that any time a check engine light comes on it is important to have checked because it could lead to a potentially serious problem(s).

The problem is running lean not rich meaning less fuel per say. This combined with the code which can cause the symptoms the vehicle is showing result in the need of the above testing that I posted.

Of course just to be sure as I stated you would also want to check timing. If these codes were old it is still a problem that needs fixed as it is at least contributing to the problem. If a problem is fixed then most codes after a correct drive cycle will reset if the problem is no longer present unless they are only history codes. You could in deed check fuel such as pressure and if pressure holds and then preform an injector leak down test, this would cause a rich condition if dumping too much fuel not a lean condition.

Thanks,

Joe

Ask Your Own Toyota Question
Customer reply replied 2 years ago
OK, I'm trying to go through the troubleshooting procedures in the OEM repair manual and they often differ depending on if the car has California emissions or not. The emissions sticker on the hood has CAL at the bottom which I assume means California emissions, but I don't know the history of the car (it has 175,000 mi. on it) and it might just have a non-CAL engine. Can you suggest a way I can confirm what emissions package the engine has? Thanks.
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 Joe Your Own Question
Joe
Joe
Joe, ASE Certified Technician
Category: Toyota
Satisfied Customers: 7,560
7,560 Satisfied Customers
Experience: ASE, electronics, Marine inboards and electronics, automotive drivability, all around repair tech,

Joe 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

1,115 satisfied customers

16 years of experience

Marty

Marty

ASE Certified Technician

199 satisfied customers

ASE & Bosch Master Tech. 30 years experience.

Amedee

Amedee

Toyota Technician

1,245 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

13,102 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
toyota camry LE: Hi! My check engine light came on about 6
Hi! My check engine light came on about 6 weeks ago. Diagnostic test said it was the catalytic converter and the replacements would cost me over $3000 with labor and parts. I don't have $3000 and the … read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
Toyota Camry: Hello, I have a 1997 Toyota Camry (4-cylinder)
Hello, I have a 1997 Toyota Camry (4-cylinder) with just over 200,000. It's been running good - no smoke. A few months ago, got the fault code P0420. Re-seated the gas tank cap, and the problem went a… read more
ImYourCarGuy
ImYourCarGuy
Associate Degree
53 satisfied customers
Camry LE: I have a 6 cyclinder toyota camry, 200,000 miles,
I have a 6 cyclinder toyota camry, 200,000 miles, no slipping but has started making a growling noise. Is this possibly a bearing in the transmission and is it worth rebuilding. Thanks, Jay… read more
ted ritter
ted ritter
Team Leader/toyota master tech/retired
High School or GED
2,692 satisfied customers
Toyota Camry: I have a 2001 toyota camry with a 4 cyl engine
I have a 2001 toyota camry with a 4 cyl engine with the following code. P0420 Catalyst system efficiency Below threshold ( Bank 1) can someone what problems cause this code to come up.… read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
2003 toyota camry: with a 4cyl..below threshold..new o2..cel stays
i have a 2003 toyota camry with a 4cyl. It keeps getting a CEL with code P0420 Is this the right code description: "Catalyst deficiency below threshold bank 1"? Am I right to assume that bank 1 is the… read more
Ron Z.
Ron Z.
Vocational, Technical or Trade Scho
2 satisfied customers
2000 toyota Camry LE: 2.2l..cranking..few seconds..fuel pump run
I have a 2000 toyota Camry LE with a 5sfe 2.2l engine. After the car sits over night the fuel must be draining back into the tank as it takes alot of cranking to get it running. I turn the engine over… read more
Dj
Dj
Auto Failure Analysis & Inspections
High School or GED
1,360 satisfied customers
98 toyota camry: a 2.2 4 cyl..p0420..catalyst..catalytic converter
i have a 98 toyota camry with a 2.2 4 cyl, that has a p0420 code- catalyst efficiency below threshhold. i replaced the catalytic converter, and cleared the code. the same code is triggered again. both… read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
change the exhaust manifold why cant you just change the o2 sensor
why do you need to change the exhaust manifold why cant you just change the o2 sensor on the poo31 code.… read more
Victor
Victor
Diagnose & Repair cust. vehicles
Associate Degree
752 satisfied customers
Toyota: Corolla..oxygen sensor..c my check engine light was..code read
Hello! :-) I have a 2004, Toyota, Corolla. About two weeks ago I put in a new oxygen sensor b/c my check engine light was on and the code read P0133. Yesterday, my check engine came back on and I'm ge… read more
TIM MOHR
TIM MOHR
SHOP OWNER
Master's Degree
8,037 satisfied customers
99 Toyota camry: cyl..on hwy yesterday, began loud rattle/knock.
99 Toyota camry, 2.2 4 cyl. On hwy yesterday, began loud rattle/knock. Extreme loss of power. Oil pressure OK, oil clean & full, Not hot, nothing out of tail pipe. Do these motors have Hydraulic lifte… read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
Cyl..4wd..runs good..Check engine light comes on another 1000 miles
P0420 - catalyst efficiency below normal (bank 1) My 4 cyl 4wd pick-up has two cats; I just replaced both cats and both O2 sensors 20,000 miles ago. Truck runs good - no other problems. Check engine l… read more
Genchi Genbutsu
Genchi Genbutsu
Toyota Master Technician
Vocational, Technical or Trade Scho
3,761 satisfied customers
Supra: non turbo..rebuilt..air intake..the catalytic converter is
i have a 1986.5 supra, non turbo. Engine has been rebuilt top/bottom, but to spec. Only modification is an after market air intake, new headers and the catalytic converter is no longer on the car. als… read more
Skyvisions
Skyvisions
ASE Certified Technician
High School or GED
13,102 satisfied customers
2000 Camry has code p0240. The catalytic converter was replaced
2000 Camry has code p0240. The catalytic converter was replaced 18 months ago. What should be the fix for this?… read more
Skyvisions
Skyvisions
ASE Certified Technician
High School or GED
13,102 satisfied customers
94 toyota: acceleration..PU..all cylinders have equal compression
Hello, The acceleration on my 94 Toyoto (v6) PU has gotten progressively worse. The problem started after I had a head job done 2 yrs ago. recent test shows all cylinders have equal compression. Recen… read more
Skyvisions
Skyvisions
ASE Certified Technician
High School or GED
13,102 satisfied customers
2000 Toyota Echo: check engine light that will not go away..o2 sensors
Hello, I have a 2000 Toyota Echo with the check engine light that will not go away. The ODB code 0171 indicated bad O2 sensors. Both sensors have been replaced. I am still getting the same code. What … read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
1991 Toyota Camry: misfiring..rough..stalling..neutral and feather
I have a 1991 Toyota Camry 2.0L. Tonight the car began misfiring at highway speed and when It was stopped The car idled rough would almost dip down to stalling than bounce back up and down had to drop… read more
Kyle N
Kyle N
Automotive Technician
Vocational, Technical or Trade Scho
3 satisfied customers
88 Toyota Supra: Turbo..about zero psi..throttle..instrument panel
Have 88 Toyota Supra Turbo. Not getting much boost pressure, will get from negative up to about zero psi after about 3 second delay on hard acceleration (100% throttle) and drops off immediately on le… read more
Sam C
Sam C
Service Manager
Almost a liberal arts!
739 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