2006 Jeep Grand Cherokee 5.7L engine, Hemi, sensor code P1129
The OBD is not that simple.
All it is saying is that it does not like the air/fuel mixture.
That can be from fouled spark plugs, an open gas cap or other intake leak, a bad O2 sensor, PVC foam on the air mass sensor, throttle position sensor, etc.
It is just like any carb engine when the mixture is bad.
You can't just read a number and know what to replace.
You have to have a feel for the symptoms.
And if there are no other symptoms, it could be the code is simply the only thing wrong.
Personally my best guess would the air mass sensor.
Look the inside of the oil cap. If there is foam there, then there is likely foam in the air mass sensor as well. PVC systems always throw foam into the sensor, and the only solution is to splice longer hoses into the system and into a condenser of some sort. This is worse in northern climates, in the winter. Most cars in cold conditions have this happening all the time. But as long as the light goes off eventually, don't worry about it.
Jul 28, 2010 |
2006 Jeep Grand Cherokee