CEL P0171, cleaned MAF, fastest way to get ready for smog check?

A

Arv

New member
What is the fastest way to get your rig to pass smog after cleaning the MAF?
1. pull fuse
2. take it to auto store and have them reset with reader
3. just drive it around untill the CEL goes out

I know that 1 and 2 would require you to drive it around for around a 100 miles before it's ok to smog your rig but I was just wondering which method would be faster since my registration is due in 2 days.

Thx!
 
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After I cleaned the bajeezuz out of my MAF when I got that code, I just pulled the battery for 10 minutes and the code was nowhere to be found.
 
JEL said:
After I cleaned the bajeezuz out of my MAF when I got that code, I just pulled the battery for 10 minutes and the code was nowhere to be found.
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That'll show up when you get a smog check right away, that's why you have to drive it around for at least 100 miles or even 200 to clear that out of the system.
 
Just to be clear, pulling the battery cable or EFI fuse and clearing codes with a scanner will have the same effect. It makes zero difference which you do. All codes will be instantly erased and all readiness monitors will be reset to NOT READY. Many states with smog checks will not pass you unless all monitors show COMPLETE (including my beloved NJ). Some allow one NOT READY. Getting the CAT EFFICIENCY monitor to complete can be a real beyotch, especially on the two-cat Cali-type systems like mine, including all '01 and '02.

Mine took 3 months the last time I had to disconnect the battery--good thing I wasn't scheduled. No MIL, just refused to complete even though I did the drive cycle as best I could. Try to drive 45mph for 16 minutes in NJ. Fuhgeddabouddit! Go 45 on an Interstate and someone will shoot you. Try it anywhere else and you will hit lights or stop signs anywhere except the Pine Barrens. It finally went complete a week before I was due for a new sticker.
 
TheDurk said:
Just to be clear, pulling the battery cable or EFI fuse and clearing codes with a scanner will have the same effect. It makes zero difference which you do. All codes will be instantly erased and all readiness monitors will be reset to NOT READY. Many states with smog checks will not pass you unless all monitors show COMPLETE (including my beloved NJ). Some allow one NOT READY. Getting the CAT EFFICIENCY monitor to complete can be a real beyotch, especially on the two-cat Cali-type systems like mine, including all '01 and '02.

Mine took 3 months the last time I had to disconnect the battery--good thing I wasn't scheduled. No MIL, just refused to complete even though I did the drive cycle as best I could. Try to drive 45mph for 16 minutes in NJ. Fuhgeddabouddit! Go 45 on an Interstate and someone will shoot you. Try it anywhere else and you will hit lights or stop signs anywhere except the Pine Barrens. It finally went complete a week before I was due for a new sticker.
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Thanks for the reply! However I still don't know whether its better to do (1,2 same result) or option 3 and just wait for the code to clear (that will happen right?).
From what I am getting here so far, it might be quicker to do 3, just drive it around instead of clearing the code. This way I don't reset everything (all the readiness monitors) by doing 1 or 2. OR all of them are messed up anyway by the fouled MAF so might as well pull the fuse since It also looks like that the CEL/MIL needs to be out for the readiness monitor drive patterns to count.

So I need to follow more than one drive pattern depending on what my sticker under the hood says about the components that I have?

Am I getting this right or wrong? :-(

Guess I'm not getting it smog-ed anytime soon.
 
Arv said:
Thanks for the reply! However I still don't know whether its better to do (1,2 same result) or option 3 and just wait for the code to clear (that will happen right?).
From what I am getting here so far, it might be quicker to do 3, just drive it around instead of clearing the code. This way I don't reset everything (all the readiness monitors) by doing 1 or 2. OR all of them are messed up anyway by the fouled MAF so might as well pull the fuse since It also looks like that the CEL/MIL needs to be out for the readiness monitor drive patterns to count.

So I need to follow more than one drive pattern depending on what my sticker under the hood says about the components that I have?

Am I getting this right or wrong? :-(

Guess I'm not getting it smog-ed anytime soon.
Click to expand...

Mostly right. Yes, 3 is probably faster than 1 or 2, although some codes can take their sweet time to reset after a cure. The only two readiness monitors that take much time are EVAP and CAT EFFICIENCY. A scanner, even a cheap one, will tell you if any monitors are NOT READY and which ones, so you can limit yourself to that drive pattern. If I were you, I'd run the CAT drive pattern and that will probably give enough time for the P0171 to reset and for all the other monitors to go to COMPLETE. As soon as the light goes off, restart the CAT drive pattern from the beginning. Then go scan it to confirm you have all monitors READY.

There is really no excuse for not buying a cheapo scanner at Wal-Mart or Amazon. It will work on all 1996+ cars and is just so handy to keep in the glove box or under the seat. Or buy a Bluetooth adapter and the Torque app if you have an Android smartphone. Either way it's under $30.
 
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TheDurk said:
Mostly right. Yes, 3 is probably faster than 1 or 2, although some codes can take their sweet time to reset after a cure. The only two readiness monitors that take much time are EVAP and CAT EFFICIENCY. A scanner, even a cheap one, will tell you if any monitors are NOT READY and which ones, so you can limit yourself to that drive pattern. If I were you, I'd run the CAT drive pattern and that will probably give enough time for the P0171 to reset and for all the other monitors to go to COMPLETE. As soon as the light goes off, restart the CAT drive pattern from the beginning. Then go scan it to confirm you have all monitors READY.

There is really no excuse for not buying a cheapo scanner at Wal-Mart or Amazon. It will work on all 1996+ cars and is just so handy to keep in the glove box or under the seat. Or buy a Bluetooth adapter and the Torque app if you have an Android smartphone. Either way it's under $30.
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Thx again! ok, I will do #3 then. Yeah I was looking into those BT readers + Torque a while back but got busy. Not really for CEL codes but more like used as a scanguage. I just swing by one of the auto parts store and have them read the codes for me. Anyways CELs are far and few in between for me, this is really the only code I deal with between 4 cars in almost 20 years. Knock on wood.

Last question, I was under the impression the CEL needs to be off before any of the driving patterns count. But it sounds like you're saying that some of that will count and start doing the CAT pattern while the CEL is on?

Thx!
 
Arv said:
Thx again! ok, I will do #3 then. Yeah I was looking into those BT readers + Torque a while back but got busy. Not really for CEL codes but more like used as a scanguage. I just swing by one of the auto parts store and have them read the codes for me. Anyways CELs are far and few in between for me, this is really the only code I deal with between 4 cars in almost 20 years. Knock on wood.

Last question, I was under the impression the CEL needs to be off before any of the driving patterns count. But it sounds like you're saying that some of that will count and start doing the CAT pattern while the CEL is on?

Thx!
Click to expand...

No, you are correct about the CEL, but the P0171 MAF test is not one of those that requires a specific driving pattern. It is more or less continuous (2 trip detection). I just figure it will help clear the code by doing some varied driving then doing it again as in the CAT pattern. If you weren't in a big hurry I would have said just drive it until it went off. Recognize cleaning the MAF may not be enough to cure the problem.
 
TheDurk said:
No, you are correct about the CEL, but the P0171 MAF test is not one of those that requires a specific driving pattern. It is more or less continuous (2 trip detection). I just figure it will help clear the code by doing some varied driving then doing it again as in the CAT pattern. If you weren't in a big hurry I would have said just drive it until it went off. Recognize cleaning the MAF may not be enough to cure the problem.
Click to expand...

Good news! CEL was out when I started the car this afternoon. I was out of town since last Thursday so it actually only took less than a total of 50 miles of my normal driving in 3 trips, (about 14 miles one way). 2 miles of side streets to get to the freeway then about 10 miles 65-70 highway driving then another couple of miles of side streets. So I really think #3 will be quicker than resetting (1 or 2) in this particular case (P0171).

I passed by Autozone and asked if they can hook up their reader to see what state the readiness monitors were in but the guy did not know how to do it and said their reader could not do it. I didn't try to press him that it could, I figured I'd hit up another place tomorrow.

I see that you replied on the other thread that I posted on regarding BT + Torque combo.

Thanks for all your help!
 
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