Code PO 171 & 174
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Teching In
Joined: Jun 2007
Posts: 27
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Code PO 171 & 174 I am having a problem with lean condition codes PO171 and 174 on bank 1 and 2 on my 02 WS6
I replaced the sparkplugs, not because of this problem but cause it was time, I have replaced the Mass Air Flow Sensor
The car is stock except for SLP lid, empty cats and Corsa cat back the car has 107K miles on it.
The car intermitantly runs bad and the SES light comes on and then something will change and it will run great and the light goes out and then back to bad and the light back on.
I have reset the computer after changing the MAF sensor and still the same problem
I have not touched the o2 sensors because I am getting the lean reading means that they are reading and reporting so there for working or is this not the case, I know a vacuum leak will cause this also but there are not a lot of vacuum lines to check.
I have owned this car since it had 6000 miles on it and this is the first problem I have had that I can figure out.
Any help would be appreciated
I replaced the sparkplugs, not because of this problem but cause it was time, I have replaced the Mass Air Flow Sensor
The car is stock except for SLP lid, empty cats and Corsa cat back the car has 107K miles on it.
The car intermitantly runs bad and the SES light comes on and then something will change and it will run great and the light goes out and then back to bad and the light back on.
I have reset the computer after changing the MAF sensor and still the same problem
I have not touched the o2 sensors because I am getting the lean reading means that they are reading and reporting so there for working or is this not the case, I know a vacuum leak will cause this also but there are not a lot of vacuum lines to check.
I have owned this car since it had 6000 miles on it and this is the first problem I have had that I can figure out.
Any help would be appreciated
I just had P0174. It ended up being a hole in a PCV hose. I changed most of the PCV hoses when I swapped in my LS6 valley cover a while back. I left the original ~3" hose that connects between the PCV valve and the intake manifold and that's where the leak was.
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I had the same code P0171. There was a leak from rubber intake hose on passengerside goin into intake I just put a zip tie there and fixed the problem. It is unmetered air gettin in. If u seal it off that should help you!!
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Teching In
Joined: Oct 2009
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I was wondering if you got your problem fixed?? I have the EXACT same problem. I am going to replace the intake port gaskets and see if it works. I know there are no vac leaks. I have had this problem for a year now. It's getting worse latley. The fuel pressure is also on the list of things to check.
Teching In
Joined: Oct 2007
Posts: 14
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From: Modesto, CA
SAME problem. I have the same P0171 & P0174 codes right now. I have had a cutout installed for about a year. Would that throw any codes? I wouldn't think so since I haven't had any problems since recently. I also ONLY use Shell or Chevron gas, (premium). Any thoughts would be greatly appreciated!
Teching In
Joined: Oct 2007
Posts: 14
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From: Modesto, CA
Duh!!! I have the same P0171 & P0174 codes right now. I have had a cutout installed for about a year. Would that throw any codes? I wouldn't think so since I haven't had any problems since recently. I also ONLY use Shell or Chevron gas, (premium). Any thoughts would be greatly appreciated!
#1 cause for a 171 or 174 code is the motor pulling additional air after the MAF. Grab a can of throttle body cleaner, and start spraying your rubber hoses and intake mating surfaces while the vehicle is running and listen for the idle to increase. When it does, you've found the area of your issue.
