百合谷

最近，当我在红灯前停下时，大概几秒钟之后，车总是往前冲一下，速度表也要跳一下，每次都发生，有时还熄火。Check 灯亮，读码是P0171，SYSTEM TOO LEAN.哪位高手知道这可能是什么问题，多谢！！！

Xinxin

Post by 百合谷;3237449
最近，当我在红灯前停下时，大概几秒钟之后，车总是往前冲一下，速度表也要跳一下，每次都发生，有时还熄火。Check 灯亮，读码是P0171，SYSTEM TOO LEAN.哪位高手知道这可能是什么问题，多谢！！！

Symptoms  
You will more than likely not notice any drivability problems, although  there may be symptoms such as:      
a lack of power     detonation (spark knock)
    rough idle     hesitation/surge on acceleration.  

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 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  Possible

Solutions  
A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks  fix the problem. If you're on a tight budget, start there, but that may  not be the fix for certain. So, possible solutions include:
     Clean the MAF sensor. 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/repair as required     
Inspect all hoses and connections in the air intake system     
Inspect and/or test the intake manifold gaskets for leakage
    Check for a dirty fuel filter and proper fuel pressure     Ideally you'll want to monitor short and long term fuel trims using  an advanced scan tool     If you have access, you may want to run a smoke test

Read more at: http://www.obd-codes.com/p0171

百合谷

非常感谢

weiguang

我的车曾经有过同样的问题， 被dealer骗了800 加币换了flowmeter.
后来学会了自己清洗。 到CANADIAN TIRE 买专用的engine throttle 清洗液，10加元左右再买一卷蓝色的汽车清理手纸。打开发动机进气口的连接处，望发动机里面看， 你就会看到一个进气阀门，就是这个进气阀门被油和灰尘污染造成发动机进气不畅。先用清洗液清洗，后用手纸擦。

lookfor9855

mazda protege, 踩刹车等红灯时发动机抖动，请教什么原因，万分感谢