P0171 And P0172
11-07-2005, 07:18 PM
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P0171 And P0172 My girlfriend has a 2002 V6 Camaro. Awhile back a check engine light came because of code P0171. Then it went away. Now the engine light came back on, and the dealer gave her 2 codes, P0171 and P0172. How can it be too rich and too lean?
I'm going to clean her mass air meter tomorrow, and maybe do the O2 sensors.
Anyone have this issue before?
Is it possible the first code (P0171) is just stored in the computer, and the 2nd code (P0172) is the current reason for the check engine light? Is that maybe why she got 2 codes from the dealer?
I'm going to clean her mass air meter tomorrow, and maybe do the O2 sensors.
Anyone have this issue before?
Is it possible the first code (P0171) is just stored in the computer, and the 2nd code (P0172) is the current reason for the check engine light? Is that maybe why she got 2 codes from the dealer?
11-07-2005, 09:50 PM
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Originally Posted by neat
Is it possible the first code (P0171) is just stored in the computer, and the 2nd code (P0172) is the current reason for the check engine light? Is that maybe why she got 2 codes from the dealer?
WS6FirebirdTA00 has some good advice as well
11-08-2005, 08:56 AM
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P0171 and P0174 (Lean bank 1 and 2) are more common from a MAF sensor, but I have seen P0172/P0175 (Rich bank 1 and 2) from a MAF as well. As the previous person said, only use electronic parts cleaner to clean the MAF. Before replacing the O2 sensor, I like to swap them bank to bank and see if the code switches banks. It's more work and more time, but if the same code sets, then you don't have to buy an O2 sensor, cuz you know that's not the problem.
If the MAF is the problem, always check to see if a K&N air filter is being used. When used properly, a K&N shouldn't cause problems, but many people think if some is good, then more is better and douse the filter with oil. Then you have excessive oil with the intake charge that can contaminate the MAF.
If the MAF is the problem, always check to see if a K&N air filter is being used. When used properly, a K&N shouldn't cause problems, but many people think if some is good, then more is better and douse the filter with oil. Then you have excessive oil with the intake charge that can contaminate the MAF.
11-08-2005, 01:51 PM
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Its not code PO171 and P0174, it's 171 and 172, which is lean and rich, same bank.
I'm gonna clean the mass air, because she does have a K&N, and see what happens.
If that doesn't fix it, I'll swap the O2's and see if the code changes.
If the cleaning the mass air fixes it, how long should it take for the light to go out?
I'm gonna clean the mass air, because she does have a K&N, and see what happens.
If that doesn't fix it, I'll swap the O2's and see if the code changes.
If the cleaning the mass air fixes it, how long should it take for the light to go out?
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11-08-2005, 04:15 PM
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I know you've got a P0171 and P0172 (lean and rich bank 1). I was simply stating what codes are commonly caused by a MAF sensor and I also stated that both are possible, so it is feasible that it could be the MAF sensor. Most driveability codes need to run their test and pass on two or three consecutive drive cycles to turn the light off. Today was a GM holiday, but I could look tomorrow to be sure whether the FT codes are type A or B codes.
11-09-2005, 03:28 PM
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It needs to run and pass three consecutive tests. It can only do one test per drive cycle. I would say three days where you drive at least a couple miles each day should shut the light off, assuming the problem is fixed. You could also disconnect the battery and see if the light will come back on.
