Lexus

Lexus troubleshooting questions? Ask a Lexus Expert

Connect one-on-one with {0} who will answer your question

how to fix the following errors P0171 System Too Lean (Bank1)

Customer Question
how to fix the following...
how to fix the following errors “P0171 System Too Lean (Bank1) and P0330 Knock Sensor2 Circuit (Bank2)” on a 2000 Lexus ES300
Submitted: 13 years ago.Category: Lexus
Show More
Show Less
Ask Your Own Lexus Question
Answered in 1 hour by:
6/21/2009
Lexus Mechanic: AutoTech08, Workshop owner replied 13 years ago
AutoTech08
AutoTech08, Workshop owner
Category: Lexus
Satisfied Customers: 973
Experience: Diploma in Automotive Engineering, 30 years working experience.
Verified

 

Hi there,

 

DTC P0171 : SYSTEM TOO LEAN

 

Possible causes are :

 

Exhaust system leak.
Air intake hose loose.
Fuel line pressure.
Injector blockage.
Faulty Mass Airflow (MAF) sensor.
Faulty Engine Coolant Temperature (ECT) sensor.
Faulty A/F sensor.
Faulty ECM.

 

Quite often it is the MAF that is faulty and requires replacement.

 

DTC P0330: KNOCK SENSOR, BANK 2 (LEFT BANK)

 

Possible causes are :

 

Open or short in knock sensor circuit.
Knock sensor (loose).
Faulty ECM.

 

Testing would be required to confirm what is wrong. Since you have other other trouble codes which might be related, rectify the P0171 first and clear codes and perform the following test to check if the problem returns.

 

Start and warm engine to normal operating temperature.

Snap accelerate engine 3 times to 4000 RPM.

Retrieve trouble codes.

 

Ask Your Own Lexus Question
Lexus Mechanic: lexpert, Lexus Master tech replied 13 years ago
lexpert
lexpert, Lexus Master tech
Category: Lexus
Satisfied Customers: 9,974
Experience: Master Certified with lexus, 8 years experience with Lexus
Verified

You asked how to fix the problem not for a list of "possible" causes here.

These 2 codes are not related.

 

For the knock sensor codes you need to inspect the wiring harness around the engine to be sure there are no signs of rodent damage (chew marks) on the harness.

Knock sensor codes are common on the 1mz-fe engine. The ultimate solution here is to replace BOTH knock sensors that are located under the lower intake manifold and also replace the sub wiring harness that runs from the sensors to the main harness at the same time.

 

As far as a p0171 this is a fuel trim lean code, 95% of the time this is due to a dirty or defective mass air flow sensor on the vehicle. The MAF is located on the air filter box of the vehicle, remove the 2 phillips head screws to remove this sensor and use low pressure compressed air to clear out the internal sensors in this part, then retest the car to see if condition is improved or resolved. These typically cause lack of power on acceleration as well as reduced fuel economy.

Ask Your Own Lexus Question
Customer reply replied 13 years ago
once the MAF is replace do any codes or anything needs to reset in the car computer?
Lexus Mechanic: lexpert, Lexus Master tech replied 13 years ago
No, you would need to clear them with the scan tool or disconnect the battery to clear the codes and retest.
lexpert
lexpert, Lexus Master tech
Category: Lexus
Satisfied Customers: 9,974
Experience: Master Certified with lexus, 8 years experience with Lexus
Verified
lexpert and 87 other Lexus Specialists are ready to help you
Ask your own question now
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a lexus mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask lexpert Your Own Question
lexpert
lexpert
lexpert, Lexus Master tech
Category: Lexus
Satisfied Customers: 9,974
9,974 Satisfied Customers
Experience: Master Certified with lexus, 8 years experience with Lexus

lexpert is online now

Related Lexus Questions
What is the normal labor charge to replace the two knock
What is the normal labor charge to replace the two knock sensors on a 2000 Lexus RX300. I also have had the fault on P0171 O2 sensor for four years. I had the O2 sensor replaced by a Toyota dealership… read more
Paul M ASE Master
Paul M ASE Master
ASE Master Tech
Automotive College
100 satisfied customers
2002 Lexus ES300. 200k miles. Car is running very poorly,
2002 Lexus ES300. 200k miles. Car is running very poorly, missing and lack of power. Engine Codes: P0174, P0171, P0330, P0776. Help.… read more
Gunvir Singh
Gunvir Singh
1,949 satisfied customers
It has a error code P0328,P0174 AND P0171, 121325MILES, 2007
i have taken to a mechanic replaced knock sensor but still tyhe error is coming back … read more
trung do
trung do
CERTIFICATE OF ACHIEVEMENT
118 satisfied customers
2000 Lexus ES300 gets P0171, P0325 and P0330 together. Could
2000 Lexus ES300 gets P0171, P0325 and P0330 together. Could these all be caused by a single problem?… read more
Peter B.
Peter B.
master technition
Vocational, Technical or Trade School
2,369 satisfied customers
2001 lexus rx300. was driving around with a po330 oxygen
2001 lexus rx300. was driving around with a po330 oxygen sensor for a little while. . now yesterday the whole truck shut done. its has 10 error codes now . p0330 x 2 P1130 X 2 P1150 X 2 P1349 X2 1354 … read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
12,079 satisfied customers
2000 es300 would stall while driving ran test had codes
2000 es300 would stall while driving ran test had codes p0171 p0325 p0330 p01354 changed oil control valve bank2 car ran good for about 5 miles now the engine is still running rough and would most lik… read more
Skyvisions
Skyvisions
ASE Certified Technician
High School or GED
1,965 satisfied customers
Lexus es300: my 99 lexus es300 check engine light is on, driving
my 99 lexus es300 check engine light is on, driving about 70 mph, pushing 3500-4000 rpm's, not shifting to 4th gear, any clue why is doing that… read more
Skyvisions
Skyvisions
ASE Certified Technician
High School or GED
1,965 satisfied customers
Lexus RX300: 2001 Lexus Rx300 The scanner says P0171-
2001 Lexus Rx300 The scanner says P0171- system too lean bank 1 When you look at it in depth the data says the problem is bank2 = “ long term fuel @ 52.3 for bank 2 = ”long term fuel @ 10.9 for bank 1… read more
Toyota Service
Toyota Service
Toyota Dealership Service & CR Manager
5,625 satisfied customers
Lexus es300: Have a 2001 Lexus es300 got error codes p1030
Have a 2001 Lexus es300 got error codes p1030 and p1035? Check engine and Trac off Lights on. Any help? Thanks… read more
Ron Z.
Ron Z.
Vocational, Technical or Trade Scho
24,703 satisfied customers
Lexus ES300: Last night the check engine light came on along
Last night the check engine light came on along with the traction indicator on my 2000 Lexus ES300. I took it by the local auto parts store and pulled the following codes: P1150 P1153 P1155 P0171 The … read more
Ron Z.
Ron Z.
Vocational, Technical or Trade Scho
24,703 satisfied customers
Lexus ES300: I recently purchased a 1999 Lexus ES300 it has
I recently purchased a 1999 Lexus ES300 it has a few problems. I changed out both the OCV' s because one was out of resistance tollerance. I cleared the codes and drove it for about 10 minutes and cod… read more
AMD
AMD
Master Technician
Vocational, Technical or Trade Scho
272 satisfied customers
Lexus RX300: 2000 lexus rx300 with 93,500 miles. Engine check
2000 lexus rx300 with 93,500 miles. Engine check light on. took it to Auto Zone and the codes came up P0171 and P0330 which by definitions says Knock sensor KS 2 circuit and system too lean -bank 1. H… read more
HondaPlatinum
HondaPlatinum
Vocational, Technical or Trade School
28,352 satisfied customers
2000 Lexus ES300: following codes p0141, p0440, p0441..o2 sensor
2000 Lexus ES300 has the following codes P0141, P0440, P0441, P0446. i already replace the top O2 sensor… read more
rpmdiag
rpmdiag
High school
10,612 satisfied customers
RX: meaning of error codes : p1346 and p0171..sensor located
Hi, am working on a Lexus Jeep RX 300 and am having problem with the meaning of error codes : P1346 AND P0171 . Pls what is the meaning of the codes and where are the sensors located. Also what is the… read more
Skyvisions
Skyvisions
ASE Certified Technician
High School or GED
1,965 satisfied customers
99 lexus ES300: intake manifold..knock sensor..maf sensor..cel
My 99 lexus ES300 has a p0325 code present and bank 1 fuel trim is at -5.47. I found a rodant nest under the intake manifold, so I removed and replaced the intakes, and replaced the bank 1 knock senso… read more
Genchi Genbutsu
Genchi Genbutsu
Vocational, Technical or Trade Scho
3,854 satisfied customers
lexus: es 300..0330(rarely) odbii going off intermittently
lexus es 300 (2000) . i have a 0171 (sometimes) and a 0330(rarely) odbii going off intermittently and when they do they cause the transmission to not go into overdrive. However, I can reset the sensor… read more
lexpert
lexpert
Lexus Master tech
Vocational, Technical or Trade Scho
9,974 satisfied customers
1999 lexus es300: check engine light..trac..The mechanics..fuel filter
I just took my 1999 lexus es300 to have it fixed. My check engine light is on with the trac off light as well. The mechanics stated that I had a broken air flow meter and replaced it and changed the f… read more
Genchi Genbutsu
Genchi Genbutsu
Vocational, Technical or Trade Scho
3,854 satisfied customers
I already serviced the Mass Air Flow Sensor..same problem..guesses
Hi! I failed to mention, I already serviced the Mass Air Flow Sensor, funny thing is about 1 year ago I serviced the sensor,for the customer, for the same problem and it disappearsd until now. So, in … read more
lexpert
lexpert
Lexus Master tech
Vocational, Technical or Trade Scho
9,974 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.

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:

lexpert

lexpert

Lexus Master tech

9,974 satisfied customers

Master Certified with lexus, 8 years experience with Lexus

Skyvisions

Skyvisions

ASE Certified Technician

1,965 satisfied customers

Lexus Expert

Chris (aka - Moose)

Chris (aka - Moose)

Technician

536 satisfied customers

24 years of experience diagnosing & repairing

AMD

AMD

Master Technician

272 satisfied customers

L1 Advanced Level Diagnostics Specialist

George H.

George H.

ASE Certified Technician

227 satisfied customers

15+ years ASE Master w/L1 Drivability certification

Tim Mohr

Tim Mohr

ASE MASTER

149 satisfied customers

30 YEARS EXPERIENCE, FORIEGN AND DOMESTIC, GAS AND DIESEL

Paul M ASE Master

Paul M ASE Master

ASE Master Tech

100 satisfied customers

ASE Master Tech 20+ Years

< Previous | Next >

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