2012 Cayenne S running rough, almost jerky or bumpy feeling at low speeds and gears

[Mitchss]

Hi all, hoping for some insight or suggestions. I have a 2012 Cayenne S 4.8 V8 with 137,000 miles on it, that has always run like a champ. It has recently begun acting odd. At first I thought it was the transmission, but decided against that as it shifts properly and smoothly. When first starting out in gears 1-4, it feels like running over random bumps or engine hiccups. It’s like engine hesitation or a jerking during acceleration. After getting up to speed, it goes away and I no longer feel it. It also feels like there is erratic idling recently when I turn car on. It also occasionally exhibits a loss of power or slow acceleration when starting out before then taking off. All of this began around the same time.

After doing some research, this seems to match the symptoms of a mass airflow sensor problem. Does the 2012 Cayenne S 4.8 V8 have mass airflow sensors? There is not one on either air tube or anywhere between the two air boxes and the throttle body? Would a bad MAP sensor cause these issues?

I have an iCarsoft Auto Diagnostic Scanner POR V2.0 and have checked for fault codes, but none show. I have also not gotten any other warnings from the dash.

Any suggestions or help are greatly appreciated!

[scanner-1]

That definitely sounds like symptoms of a MAP (or MAF) sensor issue.

My 2011 CTT will on occasion behave like you describe and it is easily remedied by removing the sensor and spraying it with MAF sensor cleaner. 

I'm guessing this happens about every 20,000 miles or so on mine with  100k+ miles. I bought a new sensor just in case, but it just rides along in the glove compartment waiting for the day when the cleaner stops working.

If I let mine go long enough, it will eventually throw a "P1637 Pressure sensor ahead of throttle valve" code.

Pretty sure your engine has at least one, check this part #: 94860618000, 

 

Edited March 26 by scanner-1