DTC's P0172 and P0175 1997 GMC 5.7 Sierra 1500

GMC C1500
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CRANK65
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I have a 1997 GMC 1500 with a 5.7 L Vortec and I keep getting DTC's P0172 and P0175. I have replaced the mass airflow sensors twice, new wires, spark plugs and I have just put a new air intake on the truck and had some exhaust work done, new muffler. I was getting the codes before the new intake (AEM brute force intake) and exhaust so I am sure that those parts didn't cause them. Just wondering what steps I need to take to see about getting the problem fixed. I appreciate any suggestions. BTW: The truck has 71,500 miles on it now and I have been fighting with those codes for a few thousand miles now; I keep clearing and they keep coming back.
Mar 2, 2006 at 1:20 PM
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MVANNESSJR
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Have you tried disconnecting the battery and letting the computer values reset themselves?
Mar 3, 2006 at 2:59 AM
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CRANK65
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I haven't tried disconnecting the battery, I was using a code scanner and cleared the codes with it. I had read that disconnecting the battery wouldn't reset the codes so that's why I was using the scanner.
Mar 3, 2006 at 9:34 AM
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MVANNESSJR
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That's correct, it may not reset the codes, but disconnecting the battery will allow the computer to re-learn its fuel and air calculations in most vehicles. Try disconnecting the battery for about 5 minutes and then start the vehicle. The computer should take into account the new air/fuel ratios and the problem will likely go away.
Mar 3, 2006 at 2:59 PM
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CRANK65
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I will give that a shot and see what happens. It can't hurt anything that's for sure.
Mar 3, 2006 at 3:22 PM
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CRANK65
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I unplugged the battery cable to let it reset to new values and it worked for a few days but code is back again. I am going to try to take the oxygen sensor off and see what it looks like at the tip, to tell if maybe the engine is really running rich.
Mar 11, 2006 at 12:03 PM