P0174故障码，适用于所有汽车制造商，意思是系统(空燃比)太稀 (第2排)(System Too Lean (Bank 2))。
提示：快速查找故障码，可以关注“”公众号，回复故障代码，如：“P0174”，即可获得对应故障码解释和解决方案。
背景知识：燃油修剪是指电子控制单元(ECU)通过增加或减少喷油器打开时间的方式来控制燃油输送，从而使发动机获得最佳空燃比(空气对汽油质量比为14.7：1)。空然比太浓是指燃油输送量过大，空然比太稀是指燃油输送量过小。如果自适应燃油控制系统已经达到了补偿极限，而空燃比仍然很稀的话，该故障码就会出现。故障原因包括空气流量(MAF)传感器之后的空气泄漏，PCV系统泄漏，氧传感器故障，氧传感器附近排气泄漏，EGR泄漏，空气流量(MAF)传感器故障，燃油滤清器太脏，燃油泵供油不足，燃油压力调节器故障，喷油器阻塞，发动机转速传感器故障，电子控制模块(PCM或ECM)故障等。
当汽车排除故障之后，往往还需要清除故障码。清除故障码的时候，应严格按照特定车型所规定的故障代码清除方法来进行，千万要注意不能简单地去拆除蓄电池负极搭铁线来清除故障代码。否则，有可能会出现下面提到的两种情况异常：第一，引起一些车型的控制中心电脑失去正常记录，很多车主都知道，大部份车型的中央电脑是具有记忆功能的，如果拿掉电池负极的连接线后，就会清除掉存储在随机存储器中发动机运行的有用数据，从而使汽车在维修后的相当长一段时间内性能不好，又可能会在行驶不长时间后，又出现处理过的故障码；第二，还会造成某些功能的丧失，例如音响锁止这个功能就是常见状况之一，这时，就需要按照很麻烦的修复程序对音响系统进行解锁，才能恢复音响系统的正常功能。
你英语好的话就明白什么意思，故障码P1106 Barometric Pressure Circuit Range/Performance
故障码P1107 Barometric Pressure Circuit Low Input
故障码P1108 Barometric Pressure Circuit High Input
故障码P1121 Throttle Position Lower Than Expected
故障码P1122 Throttle Position Higher Than Expected
故障码P1128 MAP Lower Than Expected
故障码P1129 MAP Higher Than Expected
故障码P1149 Primary HO2S (Sensor 1) Circuit Range/Performance Problem
故障码P1162 Primary HO2S (No. 1) Circuit Malfunction
故障码P1163 Primary HO2S (No. 1) Circuit Slow Response
故障码P1164 Primary HO2S (No. 1) Circuit Range/Performance
故障码P1165 Primary HO2S (No. 1) Circuit Range/Performance
故障码P1166 Primary HO2S (No. 1) Heater System Electrical
故障码P1167 Primary HO2S (No. 1) Heater System
故障码P1168 Primary HO2S (No. 1) LABEL Low Input
故障码P1169 Primary HO2S (No. 1) LABEL High Input
故障码P1253 VTEC System Malfunction
故障码P1257 VTEC System Malfunction
故障码P1258 VTEC System Malfunction
故障码P1259 VTEC System Malfunction
故障码P1297 Electrical Load Detector Circuit Low Input
故障码P1298 Electrical Load Detector Circuit High Input
故障码P1300 Multiple Cylinder Misfire Detected
故障码P1336 CSF Sensor Intermittent Interruption
故障码P1337 CSF Sensor No Signal
故障码P1359 CKP/TDC Sensor Connector Disconnection
故障码P1361 Intermittent Interruption In TDC 1 Sensor Circuit
故障码P1362 No Signal In TDC 1 Sensor Circuit
故障码P1366 Intermittent Interruption In TDC 2 Sensor Circuit
故障码P1367 No Signal In TDC 2 Sensor Circuit
故障码P1381 Cylinder Position Sensor Intermittent Interruption
故障码P1382 Cylinder Position Sensor No Signal
故障码P1456 EVAP Emission Control System Leak Detected (Fuel Tank System)
故障码P1457 EVAP Emission Control System Leak Detected (Control Canister System)
故障码P1459 EVAP Emission Purge Flow Switch Malfunction
故障码P1486 Thermostat Range/Performance Problem
故障码P1491 EGR Valve Lift Insufficient Detected
故障码P1498 EGR Valve Lift Sensor High Voltage
故障码P1508 IAC Valve Circuit Failure
故障码P1509 IAC Valve Circuit Failure
故障码P1519 Idle Air Control Valve Circuit Failure
故障码P1607 ECM/PCM Internal Circuit Failure A
故障码P1655 SEAF/SEFA/TMA/TMB Signal Line Failure
故障码P1656 Automatic Transaxle
故障码P1660 Automatic Transaxle FI Signal A Circuit Failure
故障码P1676 FPTDR Signal Line Failure
故障码P1678 FPTDR Signal Line Failure
故障码P1681 Automatic Transaxle FI Signal A Low Input
故障码P1682 Automatic Transaxle FI Signal A High Input
故障码P1686 Automatic Transaxle FI Signal B Low Input
故障码P1687 Automatic Transaxle FI Signal B High Input
故障码P1705 Automatic Transaxle Concerns
故障码P1706 Automatic Transaxle Concerns
故障码P1738 Automatic Transaxle Concerns
故障码P1739 Automatic Transaxle Concerns
故障码P1753 Automatic Transaxle Concerns
故障码P1758 Automatic Transaxle Concerns
故障码P1768 Automatic Transaxle Concerns
故障码P1773 Automatic Transaxle Concerns
故障码P1785 Automatic Transaxle Concerns
故障码P1786 Automatic Transaxle Concerns
故障码P1790 Automatic Transaxle Concerns
故障码P1791 Automatic Transaxle Concerns
故障码P1792 Automatic Transaxle Concerns
故障码P1793 Automatic Transaxle Concerns
故障码P1794 Automatic Transaxle Concerns
故障码P1870 Automatic Transaxle Concerns
故障码P1873 Automatic Transaxle Concerns
故障码P1879 Automatic Transaxle Concerns
故障码P1885 Automatic Transaxle Concerns
故障码P1886 Automatic Transaxle Concerns
故障码P1888 Automatic Transaxle Concerns
故障码P1890 Automatic Transaxle Concerns
故障码P1891 Automatic Transaxle Concerns
