RPM creep?

I just started noticing this this past month. When I'm rolling to a stop at a stop sign or red light, I clutch in, shifter is still in gear, rpm drops to a normal 900ish rpm but then immediately creeps back up to 1400ish on its own even with my foot still on the clutch pedal. I'm not on the accelerator pedal either (or even by accident for that matter). Once I come to a complete stop (shifter still in gear, foot still on clutch pedal) then the rpm drops to normal.

 

If I throw the shifter into neutral and then slow to a stop with my foot on the clutch pedal then it's all normal and theres no uptick in rpm.

 

85k on the odo. Original clutch. No engine mods or tunes.

 

Any idea what this is? Thanks!

 

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Mass Air Flow sensor, pull it and spray the crap out of it with sensor clean. ONLY sensor clean no other like brake clean or carb cleaner they will leave a residue which will kill it.

 

Let us know how it goes after you have done that

Find CRC Mass air flow cleaner. I use this twice a year on all my Subaru's, and my other cars I have. I do it when I change the intake filter or clean it.

Following for potential solution as my car is acting similarly.

update, bought some MAF cleaner. Havent had a single ounce of time to use it yet. Will report back when I do, hopefully this weekend.

 

Im wondering if the MAF in my camry also needs cleaning as 1 to 2nd shift are horribly laggy. Engine can be revving to 3k and still not shift to 2nd. Super annoying when getting out of a stop sign or light. When it does finally shift it jerk the car like crazy. Does MAF affect transmission shifts?

Depends on how the control of the gearbox is on the camry - if it uses a vacuum hose from the manifold to the gearbox that hose might have a leak or you have a bad MAP sensor.

So just cleaned the camry and gave it some good mileage both on and off highway and wow, MAF cleaner fixed the problem. The little sensor on the MAF was pretty black. The cleaner cleaned it up right away. No more hesitation from the camry.

 

Cleaned the Suby also, gave it a run around the block and it seemed like i dont get RPM creep anymore. Weird thing was that when I first put the MAF back on, my check engine lights came on, cruise control light was on, and "sport" mode was blinking. Had to shut the car off and on about 5x before everything was normal again. Threw the P0102 and P0113 error codes. I havent given the car the same mileage as the camry but I will at some point. Going around the block seemed to prove the MAF cleaner worked. My MAF sensor on the suby was also black with dirt.

 

Ill report back again once i give the suby a good run.

Had a chance to run the car for about 100miles. Still experiencing the rpm creep problem in the same way. Car feels like it pulls a tad stronger after the cleaning but rpm creep is still present when I'm in gear and slowing down.

 

Ideas?

Edited October 27, 2019 by kaitanium

Check for vacuum leaks somewhere? That or maybe disconnect and clean your TPS.

Mine has been doing basically the same.

 

Diagnosis at the shop started today and so far no answers.

 

Before sending it to the shop I replaced the throttle body (with integrated TPS), the accelerator pedal, smoke tested, etc and found nothing made any difference.

 

Just before sending it to the shop it started giving me a check engine light for a too rich condition.

I'm sort of having this problem too. I've tried cleaning the MAF and changing the front O2 sensor, but I haven't put on many miles on the new front O2 sensor to see if that changed anything. No ECU reset as I was hoping to see the opposite fuel trim corrections with the new part. So far, it's going in that direction, but nothing drastic. I need to put more miles on it to see if it straightens itself out. If not, I'll just reset the ECU and assume the O2 wasn't the problem.

Forgot to mention that. Changed my front o2 as well. No change.

 

My car is heavily modified and no longer has a MAF so my solution may not be applicable to a stock vehicle.

Interesting - in my case it was the MAF. The O2 didn't change anything for me either. If you're on speed density, you might want to log your AVCS to make sure it's matching on both sides. If one of your OCVs is reacting slowly, it could make you run lean. And then fuel trims compensate and make you rich on the other bank. Otherwise, maybe I'd check EGR solenoids/valves?

 

Please keep this thread updated with what it ends up being. It's interesting that you're exhibiting this on speed density. I tuned my other car on speed density, and haven't had nearly as many problems as my OBXT on a MAF tune.

It seems to have TiC a bit stumped as well.

 

Passed a leak-down test, so thats good.

 

They are digging further when the tuner is in the shop starting tomorrow.

 

I created my own thread about the issue a while back.

 

https://legacygt.com/forums/showthread.php?t=279330

So my very similar issue has now been resolved.

 

The barometric sensor on the secondary air injection pump failed. My secondary air pump is long gone but the sensor is kept during that pump delete.

 

Seeing as how OP has an 09, there is a possibility we had the same issue.

So my very similar issue has now been resolved.

 

The barometric sensor on the secondary air injection pump failed. My secondary air pump is long gone but the sensor is kept during that pump delete.

 

Seeing as how OP has an 09, there is a possibility we had the same issue.

 

hmm...good to know ill check it out. Where is this sensor located and how would i know it failed?

Its part of the secondary air injection pump and must be retained when deleting the useless air pump.

 

It's on the drivers side of the engine bay. Googling "secondary air injection pump" ought to bring you up some pics/ videos on deleting it.

i probably dont want to delete anything unless for good reason, if its useless and its ok staying in there then i rather leave it. I dont want to do anything to the engine really because of CA smog laws. Even if this doesnt affect smog checks, smog centers here fail you for even a fully legal AOS which is mind blowing.

 

but you said the barometric sensor could be broken, i assume ill just need to replace that if i can replace it....and if i can find it. SOunds like its a pricey part.

Edited January 4, 2020 by kaitanium

i probably dont want to delete anything unless for good reason, if its useless and its ok staying in there then i rather leave it. I dont want to do anything to the engine really because of CA smog laws. Even if this doesnt affect smog checks, smog centers here fail you for even a fully legal AOS which is mind blowing.

 

but you said the barometric sensor could be broken, i assume ill just need to replace that if i can replace it....and if i can find it. SOunds like its a pricey part.

Its extra pricey because the sensor isn't sold separately.

 

You have to buy the entire air injection pump.

 

Can't blame you for not wanting to mess with the delete because of smog issues. The pump is emissions related. It's meant to help pre-heat the cat for better efficiency, or some nonsense my state doesn't care about.

Its extra pricey because the sensor isn't sold separately.

 

You have to buy the entire air injection pump.

 

Can't blame you for not wanting to mess with the delete because of smog issues. The pump is emissions related. It's meant to help pre-heat the cat for better efficiency, or some nonsense my state doesn't care about.

 

bummer. Yea, CA is CA proud of their nonsense.

 

was this the pump that im seeing that was recalled awhile back?

https://legacygt.com/forums/showthread.php/air-pump-recall-07-09-legacy-outback-turbos-and-more-257176.html

https://repairpal.com/recall/16V738000

 

This part i assume? https://www.ebay.com/itm/2007-2009-Subaru-Outback-XT-air-pump-/323822489545?_trksid=p2385738.m4383.l4275.c10

 

Would you know if a OBD can verify if this is broken or not? I do have the torque app but not sure if it would verify anything for me.

Yes that is the pump.

 

IIRC it is not the pump that has been recalled, it is the relay that sends power to the pump.

 

You will need to view the barometric pressure. (not sure if torque app would help) Mine was sitting at the minimum value (6psi) and never changed.

getting reports that there is no sensor in there

Look at the procedure for deleting the air pump. It details hacking off and retaining the sensor.

 

I'll see if I can dig it up if/when I get a few minutes.

 

There's %100 a sensor, I believe it is more "on" than "in" the secondary air injection pump.

 

 

 

Edit:

 

Edited January 6, 2020 by gkinslow

Its in the black plastic part on top of the solenoid that has been already removed in this pic. You can slightly make out some holes in the top which I believe are the sensor ports.

 

I've had to try remedy a few cars that have had the sensor not installed after deleting the air pump. With it unplugged a permanent atmo reading is given to the ECU so you can tune around it quite easily if at a constant elevation but elevation changes cannot be compensated by the ECU this way so it won't run perfectly

 

trying to wrap my head around where that "black plastic piece" is in relation to this pic:

https://i.ebayimg.com/images/g/hAoAAOSwTzRc8cQ0/s-l1600.jpg

 

I guess it doesnt matter. I can just buy a whole new pump and be ok if im understanding right.