m*****8 发帖数: 30 | 1 最近check engine的灯亮了,读了code是P0171 System too Lean (Bank 1),我把
spark plugs 和fuel filter 都换了,还亮。不知道是不是什么大问题。车型是03年
carolla |
c*******e 发帖数: 655 | 2 System too Lean,你换spark plugs 和fuel filter 有什么用,检查进气系统有没有漏
气先。 |
c***d 发帖数: 275 | |
c***d 发帖数: 275 | 4 Your MAF is dirty. Every corolla has this problem and no exception as long
as it runs on earth. |
h*****e 发帖数: 1153 | 5 去买瓶MAF cleaner清理一下MAF sensor就行了 |
m*****8 发帖数: 30 | 6 我把MAF弄下来看了,两条细线很亮,应该还算干净,不过还是用异丙醇和正己烷洗了
下,还是没用,CEL还亮着。有人说是O2 sensor的问题,不知道是不是要换他 |
d*b 发帖数: 21830 | 7 检查EGR vacuum hose,这是最简单的,也是最容易出问题的地方,楼上人早说了N边了。
【在 m*****8 的大作中提到】 : 我把MAF弄下来看了,两条细线很亮,应该还算干净,不过还是用异丙醇和正己烷洗了 : 下,还是没用,CEL还亮着。有人说是O2 sensor的问题,不知道是不是要换他
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d*b 发帖数: 21830 | 8 MAF属于ECU检测范围, MAF故障的话OBD进入fail-save mode, ECU也不会只给你一个
system too lean的code了
凡事用点脑子多想想。
【在 c***d 的大作中提到】 : Your MAF is dirty. Every corolla has this problem and no exception as long : as it runs on earth.
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j****t 发帖数: 131 | 9 Did you clear the error code to see whether it came back ? |
f**********n 发帖数: 3081 | 10 网上找的,
Any time I've seen the P0171 code on other vehicles, that exactly what it was #1) dirty/faulty MAF sensor. 2) Vacuum leak. Usually somewhere around the upper intake manifold (gasket, O-ring, etc..)
To look for vacuum leaks, you could use a hose in the ear (yeah, I know, Don's getting funny!). Seriously, use a vacuum hose with one end near your ear and the other end moved around the engine to likely leak points - hose nipples, gaskets, and so forth. I have actually heard a vacuum leak through the hose. Think of it as a limp stethoscope. biggrin.gif
Another way is to spray a solvent around the engine at possible leak points. A change in RPM means you found it. Problem is, then you need to clean the engine. We all do that, don't we??? whistling.gif
I've seen messages about cleaning a MAF sensor with contact cleaner - the pure stuff, not any with a lubricant in it like silicone or whatever - but be extremely gentle. The sensor is very fragile.
There is a product called CRC contact cleaner that home depot sells that you can use. DO NOT use CRC electrical parts cleaner. That is chlorinated and will trash the sensor. When you clean the MAF do not attempt to scrub the sensor with a brush. Let the contact cleaner do the work. Let it dry completely before installing it. |
f**********n 发帖数: 3081 | 11 老夫的车前天也出了 p0171, 明后天得想办法解决一下。 |
f**********n 发帖数: 3081 | 12 Causes
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 Solutions
Possible solutions include:
* In the vast majority of cases, simply cleaning the MAF sensor does the
trick. Consult your service manual for it's location if you need help. I
find it's best to take it off and spray it with electronics cleaner or brake
cleaner. Make sure you are careful not to damage the MAF sensor, and make
sure it's dry before reinstalling
* Inspect all vacuum and PCV hoses, replace if necessary
* Check for a dirty fuel filter and proper fuel pressure
http://www.obd-codes.com/p0171 |