chilton auto repair manual available free at your local public library. vid i have a 2001 Sienna with the check engine light on. had a diagostic machine check and got a code P0171 AND P0174. And it says "system too lean". Also it the diagnostic reads: O2S212 .625 mv O2S211 3.29 mv your info will be greatly appreciated. po 171 is almost always the mass airflow sensor located in the air cleaner box. start with that, its only about 150.00 for the part and is easy to replace. I took MAF off the top of the air filter with two screws and clean it and reset the check engine with ODBII code reader I called Toyota dealer in Canada it cost $245 plus tax
P0171 specifically for Toyota is generic "too lean", and very well could be MAF, but the MAF can be cleaned, recommend trying aerosol cleaner before buying a new one, and run the OBD again to see if it will give you a more specific fault code..it could be O2 sensor, MAP Intake (Manifold Absolute Pressure) and dozens of other things. No dispute here, just adding
you can choose china brand Launch X431 Creader VIII CRP129 from vipprogrammer.com, it is designed to almost vehicle, and read the ODBII diagnostic codes, als have others car diagnosis function, it is an good diy tools for owner, diagnosis and maintenance easier and cost even less. Maintenance and Service All in One, Because it has more application, like Engine Oil Reset, ABS Bleeding, and more.
Diagnostic codes are generated by your on-board computer. They tell you what problems the computer has identified with your engine. The codes are numbers. The code numbers are read by an instrument that plugs into a special jack under the dash. Auto parts stores often will check your diagnostic codes for free, or you can have your dealer do it.
Copyright © 2020 Multiply Media, LLC. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.