Service engine soon light on Sentra S 2007 ( what to do now?)

(Is it safe to drive with this light on btw? and for how long can i do this without a repair in place? I 've only had it for aday and got it right after I pumped fuel into my car which I found odd.)

My Nissan Sentra 2007 S is displaying this light steadily. I don’t see a check engine light on it and just this. Is this the same thing? The people at autozone said they are two different things and if I get justa service engine soon light this is just for maintenance like an oil change but have already gotten one a few months ago. Someone else told me that both the CEL and SES lights are both the same thing on Nissans.

Anyways I got the the system scanned at autozne and they told me it was code P0171 and it is a mass air flow sensor problem, and that i could try to spray mass air flow sensor cleaner on the part, since he says the (wire?) inside the part is probably black and that i could disconnect the battery for 30 minutes while doing this, to see if resets the system, and that in hopes the service engine soon light would go off too. But he said I may have to drive it around too, to see if this would happen just like the manual says. He says if the light doesnt go off after, I could replace the part and see if that works. Is it easy to replace on my own? The notes said “system too lean Bank1” and he said it could be taking in too much air or too much gas.

Someoen else told me this after telling them the above “A P0171 is usually caused by an air leak. That’s the first thing you should check. Check the air duct from the filter box to the throttle body to make sure there are no cracks/tears. Then check for a disconnected or crack vacuum line. Check for exhaust leaks. Do all that before you even thing about replacing the MAF sensor.”

SO what should I be doing? And l i took it to a shop some 5 or 6 months ago and they said my exhaust didn’t have any leaks and neither did my catalytic converter but i dont think both parts are the same thing on my car right? Anyways i didnt see any either when they showed me under the car. Do anyone have a video or image that shows what parts the vacuum line is on my car and how to fix that? Is the fix a universal fix for all cars for both the duct and vacuum line?

Wrong. P0171 indicates the engine controller thinks the engine is running lean. There are a dozen (or more) things that can cause this code.

After reading about all the advice and suggestions you’ve gotten I recommend you forget all that and just ask your family and coworkers for the name of a reputable shop that does diagnostic work. The people at Autozone aren’t mechanics anad don’t understand how engine electronics work.


so I checked my car and there was a tear in the air intake. Is it necessary to clean the throttle body as shown in this video 2000 2006 Nissan Sentra Throttle Body Remove, Clean, Install & Relearn - YouTube and relearn it? Would it apply to my Sentra 07 too and how would I know if it necessary to clean or not? What does relearing do?

That’s why you’re getting the lean code.

Fix the tear, and see if the light turns off.



what about the throttle body and relearning? also i was just going to tape up this part with elcctric tape. would it be safe to drive for afew days until i get the new part

If you’ve never cleaned an electronic throttle body, don’t mess with it.

Fix the tear and see if the Check engine light shuts off.


Is taping it upwith electric tape enough or would i actually have to buy a new part? I think some say thermal tape is what i should use if so Robot or human? WHat do you say?

I see cheaper 20 dollar intake hoses on amazon and one for a little over double. Would the 20 dollar one work just as well? some say the sheaper ones dont flex as well and seem softer but idk

That’s a temporary repair.

If the snorky ripped once, it’ll rip again

Replace the part

You get what you pay for.



Good work. Now tape it up until your new part arrives.

I can’t see if your throttle body is sludged or carboned up, so I don’t know.


Open the butterfly with your finger. Or screwdriver. Then wipe out the throat of the throttle body. That’s the 2 min repair. Open butterfly, release it. It closes? Then you probably didn’t damage it. Even on a drive by wire.

i put tape on the tears and it is still getting the light to come on. What can i do now? are you sure it is the intake hose? wouldnt it have gone off? thankyou btw!

where is the vacuum line on my car btw?

You drive the car a while before the light will turn off.

And don’t open the throttle body by hand.


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Can you say roughly how long I may need to drive it fpr the light to turn off? What if it’s something else too since I hear it can be many things that can cause this light to come on. How would I know how long to drive it until realizing this or something else was the problem? Also why is it necessary to replace the hose if I can just cover it in tape until the rubber disintergrates or someting?

In most cases, successfully repairing the issue that caused your light to come on will cause the check engine light to turn off automatically—but only after 10 to 20 “cycles”. A cycle, in this instance, refers to the process of turning the vehicle on, running it for some time, and turning it off again.


So if I just decided to tape it up, would the light not turn off at all after driving for some time? You don’t have a rough time frame of how long I may need to drive for my car to turn off that light? I dont know if you saw my question about taping it up, but I don’t really know how that wouldnt work too considering it would create a seal even only for some time until the rubber just falls apart completley. Is it not necessary to visit a mechanic then?

I expect the proper method to get the computer to begin to relearn the fuel injection parameters (once the intake boot tear is repaired) requires using a special scan tool to instruct the drivetrain computer this function is needed. If you don’t do it that way, hard to say how long it will take, or how many drive cycles are required. I’d expect eventually it would turn the warning light off though, provided the boot tear is the only culprit.

To put things in perspective, you lucked out b/c you found the most likely culprit yourself. This sort of thing, problems wth air/fuel mixture, can take many hours of shop diagnostic time to resolve. checking entire length of exhaust system, vacuum system, fuel injection system, ignition system etc. Suggest to re-invest your savings into paying a shop to using the scan tool method. Find a shop that has a Nissan pro-level scan tool or compatible.

As far a taping it over, or replacing the part. Suggest to make that decision based on how much the replacement part goes for. Ask at a dealership, compare to the price from an online parts vendor like Or google it. That part may only be available from a dealership.

Well again IDK if that would turn the light off with just taping it up alone? Well there is one on amazon for 20 and the next step up is 50. I was just if I could salvage it with tape for a year or however long it will hold up, I would rather go that route unless there is a real reason not to?

Also how would I find a shop such a scan tool? Just call around or what scan tool qualifies for that even? Ultimately though I’d rather spend money on what is needed unless you saw a reason not to spend on anything else (scan tool test or otherwise), if my true concern is having a vital car of my car break down later on that could have been prevented earlier… Why does a special scan tool for NIssans cost money to use vs like one at autozone?

Did the pipe dry rot and is starting to fall apart? Could pieces of rubber be flaking off and getting sucked in the engine? Did something damage it and cause the tear? Just fix it the right way unless you know what caused the tear.

It usually takes a few days to a couple weeks for the CEL to turn off on its own. Usually it’s reset by the mechanic after the repairs are complete.

The Advance auto tool lets you clear the codes I think. The Autozone one only works with the store and you bring it back in to find your codes. O’reilly makes a worker come out and do it. That’s how it is around here.

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