x******4
发帖数: 3001 | 1 车是2002 corolla LE，读了code，P0420，下面是读出来的sensor值，软件不熟，不知
道啥意思，高手帮忙看看是不是sensor的问题？哪个有问题？希望是sensor的问题。。。
多谢！ |
a******o
发帖数: 16625 | |
w****k
发帖数: 690 | 3 求问用什么软件读出来的？
。。
【在 x******4 的大作中提到】
: 车是2002 corolla LE，读了code，P0420，下面是读出来的sensor值，软件不熟，不知
: 道啥意思，高手帮忙看看是不是sensor的问题？哪个有问题？希望是sensor的问题。。。
: 多谢！
|
x******4
发帖数: 3001 | 4 软件是proscan，第二个sensor没有03，04两个值，正常吗？ |
h******r
发帖数: 1578 | |
x******4
发帖数: 3001 | 6 the upstream sensor (pre-cat) should read between ~0V - ~5V, the downstream
(post-cat) should read between ~0V - ~1V.
说明第二个sensor坏了？
测试这个sensor的性能是发动机发动时候测还是关闭发动机后把钥匙打到ON？ |
g********b
发帖数: 8461 | 7
downstream
Are you kidding? O2 sensor only jumps between 0V and 1V.
一般O2sensor的好坏是无法通过读曲线看出来的。如果O2sensor的Mileage接近或超过
120k miles的话可以考虑换掉。如果2个都达到的话可以一起换。如果问题依旧则可以
确定是Cat问题。
【在 x******4 的大作中提到】
: the upstream sensor (pre-cat) should read between ~0V - ~5V, the downstream
: (post-cat) should read between ~0V - ~1V.
: 说明第二个sensor坏了？
: 测试这个sensor的性能是发动机发动时候测还是关闭发动机后把钥匙打到ON？
|
x******4
发帖数: 3001 | 8 根据2楼给的链接，看到了这个：
To minimize this risk, it's a good idea to check the operation of the O2
sensors with a scan tool or scanner software. You should see normal
switching activity in both sensors shortly after the engine is started, with
the O2 sensor voltage switching back and forth between rich (over 0.8 volts
) and lean (less than 0.3 volts). A flat line O2 sensor reading or one that
shows little switching activity is a bad sign. The downstream O2 sensor
should slow down and go flat when the converter lights off (if the catalyst
is working). If it keeps on switching like the upstream sensor, it tells you
the catalyst is probably bad and the converter needs to be replaced.
也就是说发动以后测？
还有
Also, you need to do a little research. Check with a new car dealer or
search online for any technical service bulletins that may relate to your
problem. In some cases, a "reflash" of the engine computer may be required
if the vehicle has a history of being overly sensitive with the catalyst
monitor.
怎么知道什么型号/年份的车需要"reflash" ？丰田网上也没说明啊？ |
