I fixed P0420 for a 2000 Corolla before

You have replaced the spark plugs. But have you ever checked your Mass Air Flow Sensor? By removing the two screws, located on plastic pipe between air cleaner to throttle intake, please take a look at it. There is a little filament that reads airflow, it should be orange in color; Due to age and mileage, this filament could be covered with dirt/oil and cause fauls reading.

I fixed a 2000 corolla with the same P0420 before, it was this Mass Air Flow Sensor. After I spray the filament with electrical cleaner, the check enginer light never comes back.

所有跟帖： 

• 這個容易，不妨一試 -色大膽小- ♂ (0 bytes) () 11/12/2012 postreply 13:53:09

• OK.這個我會再搞一下 -滿地找牙- ♂ (0 bytes) () 11/12/2012 postreply 16:22:33

• 這麽做其實是增加了空氣流量，是嗎？ -史迷- ♂ (0 bytes) () 11/12/2012 postreply 17:09:43

• MAF不敏感,電腦應該少給油,好像應該是餓死貓,不是富死貓 -滿地找牙- ♂ (51 bytes) () 11/12/2012 postreply 17:34:30

• MAF的熱敏電阻有灰塵覆蓋時，我的車曾經system too lean -PolyGM- ♂ (0 bytes) () 11/12/2012 postreply 17:50:44

• With a dirty MAF, you probably will get a "system too lean" code -hardtofix- ♂ (850 bytes) () 11/12/2012 postreply 20:21:34