Quote:
Originally Posted by metallicamaster3
Code:
P1132 - Powertrain
Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Rich - Bank 1
P1152 - Powertrain
Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Rich - Bank 2
P0172 - Powertrain
System too Rich (Bank 1)
P0175 - Powertrain
System too Rich (Bank 2)
Those four fault codes just will not go away. I've replaced all O2 sensors, replaced the EGR Pressure Sensor. cleaned the MAF (which wasn't that old anyway, and wasn't dirty at all), and replaced the old spark plugs. I've also read that sometimes the OEM alternator causes voltage irregularities which could cause the injectors to fire too much fuel, so I replaced that as well. After 150 miles the fault codes still keep coming back every 20 miles or so. I pulled the plugs and they are running perfectly - no white residue (if it ran lean) and no black buildup (if it ran rich).
Here's a picture of the spark plug from cylinder 4 after 150 miles,
As you can see it's running just fine. There's no signs of the motor running rich at all - no lack of power, no smoke from the exhaust, etc.
What else could it be? Bad MAF? Bad PCM? After $135 for the alternator, $60 for each O2 sensor, $62 for the EGR pressure sensor, funds to keep throwing parts at it are getting dry. 
Gas mileage is pretty average, getting about 12-13mpg around the neighborhood and around town.
Just trying to get this bloody CEL to go away. 
 all around to the one who can figure what what's going on here! |
The codes are counter intuitive, so P1132 and P1152 are telling the ECM that the engine is running rich, the ECM will command the injectors lean mixture as indicated by the look of the sparkplug...A little scary in fact!!! Running too lean can melt pistons!!
What you need to do is take a deep breath and not throw anymore parts at it.... Rent or buy a scanner that reads live data so you can see if the O2 sensors are in fact working like they should...
We are all going to need alot more info about your truck, ie, Engine, Trans ,rear gearing ,4WD or 2WD and Year ...to really help you..!!