P0133 gone -- P0171 won't go away
#1
09-28-2009, 11:46 PM
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P0133 gone -- P0171 won't go away
Vehicle:
2000 Dodge Dakota Quad cabe
4.7L
180,000 miles
CEL came on and displayed codes P0551, P0133, P0171. After much searching, I could only find 2 O2 sensors on the truck (before after the cat convertor). I replaced the O2 Sensor BEFORE the cat convertor. I was told only CA models have 4 o2 sensors.
I cleared the computer -- the CEL light came on after 150 miles. I'm getting P0171. The truck is gobbling gas.
I can't find any sensors on the exhaust manifold. I've read thread about the PS Switch sending fluid down the harness to the O2 sensor but that seems like a long way for oil to travel!
ANy ideas?
2000 Dodge Dakota Quad cabe
4.7L
180,000 miles
CEL came on and displayed codes P0551, P0133, P0171. After much searching, I could only find 2 O2 sensors on the truck (before after the cat convertor). I replaced the O2 Sensor BEFORE the cat convertor. I was told only CA models have 4 o2 sensors.
I cleared the computer -- the CEL light came on after 150 miles. I'm getting P0171. The truck is gobbling gas.
I can't find any sensors on the exhaust manifold. I've read thread about the PS Switch sending fluid down the harness to the O2 sensor but that seems like a long way for oil to travel!
ANy ideas?
#2
09-29-2009, 12:17 AM
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Once the oil gets inside the loom It goes down hill from there. But too much oxygen in the exhaust
The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the leak the silicone potting material used to protect the circuitry There could be a downstream of the MAF sensor.
the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace if necessary
Check for a dirty fuel filter and proper
I got this off a site and pasted it Im not typing all that out lol
The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the leak the silicone potting material used to protect the circuitry There could be a downstream of the MAF sensor.
the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace if necessary
Check for a dirty fuel filter and proper
I got this off a site and pasted it Im not typing all that out lol
Last edited by pizzo; 09-29-2009 at 12:20 AM. Reason: hit send by mistake
#3
09-29-2009, 12:41 AM
Just in case you wanted to know all this I'll tell you what causes the code and you can see if any of this makes any sense.
When your truck is at normal operating temp, the air/fuel mixture is constantly changing. The PCM will force the mixture to go lean, and when the o2 signal indicates a lean mixture, the PCM will force the a/f mixture to go rich. A graph of o2 voltage would look like smooth steady curve that swings between 0V and 1V.
The PCM's fuel control is called fuel trim. Short term fuel trim is what the PCM changes to affect the air/fuel mixture and change the o2 sensor voltage. Long term fuel trim is essentially the PCM's fuel mixture memory. If the PCM had to change short term fuel trim to say, -5% for a certain length of time, the PCM would "remember" that number as long term fuel trim and then short term would return to 0.
The PCM has the ability to change fuel mixtures up to a total of 66%. Short term can go 33% + or -, and long term can go 33% + or -.
The lean code will set if the total adjustment is more than 45% total.
I say all that to say, anything that changes fuel can cause the problem. Look for low fuel pressure, a bad fuel injector, an intake or exhaust leak, exhaust restriction, MAP sensor problem or in worst case, a leaking intake or exhaust valve.
If you don't have any other codes, I wouldn't suspect a o2 sensor problem especially with a new o2. Maybe double check the connector and make sure there is no moisture in the connector that might be shorting it out.
The bad thing is, these problems are very difficult to diagnose even with a DRB and service manuals. You need to know specifics about voltages and o2 readings to know where to look. I wish you luck tho. Maybe this long winded reply will help. Maybe sticky? haha
When your truck is at normal operating temp, the air/fuel mixture is constantly changing. The PCM will force the mixture to go lean, and when the o2 signal indicates a lean mixture, the PCM will force the a/f mixture to go rich. A graph of o2 voltage would look like smooth steady curve that swings between 0V and 1V.
The PCM's fuel control is called fuel trim. Short term fuel trim is what the PCM changes to affect the air/fuel mixture and change the o2 sensor voltage. Long term fuel trim is essentially the PCM's fuel mixture memory. If the PCM had to change short term fuel trim to say, -5% for a certain length of time, the PCM would "remember" that number as long term fuel trim and then short term would return to 0.
The PCM has the ability to change fuel mixtures up to a total of 66%. Short term can go 33% + or -, and long term can go 33% + or -.
The lean code will set if the total adjustment is more than 45% total.
I say all that to say, anything that changes fuel can cause the problem. Look for low fuel pressure, a bad fuel injector, an intake or exhaust leak, exhaust restriction, MAP sensor problem or in worst case, a leaking intake or exhaust valve.
If you don't have any other codes, I wouldn't suspect a o2 sensor problem especially with a new o2. Maybe double check the connector and make sure there is no moisture in the connector that might be shorting it out.
The bad thing is, these problems are very difficult to diagnose even with a DRB and service manuals. You need to know specifics about voltages and o2 readings to know where to look. I wish you luck tho. Maybe this long winded reply will help. Maybe sticky? haha
#4
09-30-2009, 12:33 AM
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Join Date: Aug 2009
Location: Lakewood CA
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Vehicle:
2000 Dodge Dakota Quad cabe
4.7L
180,000 miles
CEL came on and displayed codes P0551, P0133, P0171. After much searching, I could only find 2 O2 sensors on the truck (before after the cat convertor). I replaced the O2 Sensor BEFORE the cat convertor. I was told only CA models have 4 o2 sensors.
I cleared the computer -- the CEL light came on after 150 miles. I'm getting P0171. The truck is gobbling gas.
I can't find any sensors on the exhaust manifold. I've read thread about the PS Switch sending fluid down the harness to the O2 sensor but that seems like a long way for oil to travel!
ANy ideas?
2000 Dodge Dakota Quad cabe
4.7L
180,000 miles
CEL came on and displayed codes P0551, P0133, P0171. After much searching, I could only find 2 O2 sensors on the truck (before after the cat convertor). I replaced the O2 Sensor BEFORE the cat convertor. I was told only CA models have 4 o2 sensors.
I cleared the computer -- the CEL light came on after 150 miles. I'm getting P0171. The truck is gobbling gas.
I can't find any sensors on the exhaust manifold. I've read thread about the PS Switch sending fluid down the harness to the O2 sensor but that seems like a long way for oil to travel!
ANy ideas?
#5
09-30-2009, 10:08 AM
Join Date: Sep 2009
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I replaced the O2 sensor that is before the cat convertor. I could not find any o2 sensors on the exhaust manifold, the only ones I coudl find were before/after the cat convertor.
Anyway, the PS Pressure swtich had leaked into the connector and I replaced it last night.
My O2 sensor had a little oil in the connector, so let it "drip" last night for acouple hours> i'd hit the connector with "electroinc connecor cleaner" to wash away the oil. I'm going to drive for a couple of days to see if I can heat up the oil the is lingering inteh wiring and then let it drip all day saturday and sunday.
I can't believe teh oil made if all the way to the O2 Sesnor! The pre-convertor sensor is on the passenger side!! Is there another oil source that I'm not aware of?
Anyway, the PS Pressure swtich had leaked into the connector and I replaced it last night.
My O2 sensor had a little oil in the connector, so let it "drip" last night for acouple hours> i'd hit the connector with "electroinc connecor cleaner" to wash away the oil. I'm going to drive for a couple of days to see if I can heat up the oil the is lingering inteh wiring and then let it drip all day saturday and sunday.
I can't believe teh oil made if all the way to the O2 Sesnor! The pre-convertor sensor is on the passenger side!! Is there another oil source that I'm not aware of?
