What is the current state of the 'engine stumble' issue?
01-23-2018, 06:13 PM
#211
In regards to the O2 sensor swap, in a few cases, including mine, there has been a marked improvement. My car isn't completely cured, but I'd have to say it's undoubtedly 80% better. The stumble has turned out to be a very complex problem, as no single fix seems to have cured it completely.
Once again, hats off to PCNA for all of their hard work in resolving this.
Once again, hats off to PCNA for all of their hard work in resolving this.
01-23-2018, 06:41 PM
#212
Does anyone know what percentage of 991s have this issue?
01-23-2018, 09:26 PM
#213
Originally Posted by tse
Does anyone know what percentage of 991s have this issue?
01-24-2018, 02:21 AM
#214
Rennlist Member
Mine was fixed then came back now it seems to be mostly gone again after the 40k service but I have a parked gas smell....rather the stumble frankly
I think they have software updates that are a patch but not a solution
I think they have software updates that are a patch but not a solution
01-24-2018, 05:51 AM
#215
After a 30k miles oil service on my 997.2 which included switching from 0W40 to 5W50 oil it seems the stumble is much less apparent if not gone for now. Will observe closely if it stays that way... 
01-24-2018, 08:31 AM
#216
Anyhoo, thanks for letting me know. I have made an appointment with my dealer for this afternoon to have them inspect the exhaust for debris and inquire why I wasn't informed of this potential issue when purchasing the car.
I suspect this will cost me a small fortune but for peace of mind...
Thanks again, this forum is truly a godsend.
01-24-2018, 08:58 AM
#217
Race Director
Originally Posted by tse
This really pisses me off, we Canadians are always getting screwed.
Anyhoo, thanks for letting me know. I have made an appointment with my dealer for this afternoon to have them inspect the exhaust for debris and inquire why I wasn't informed of this potential issue when purchasing the car.
I suspect this will cost me a small fortune but for peace of mind...
Thanks again, this forum is truly a godsend.
Anyhoo, thanks for letting me know. I have made an appointment with my dealer for this afternoon to have them inspect the exhaust for debris and inquire why I wasn't informed of this potential issue when purchasing the car.
I suspect this will cost me a small fortune but for peace of mind...
Thanks again, this forum is truly a godsend.
The Canadian part was a joke ... no need for an appointment
Only affects yellow cars.
Last edited by STG; 01-24-2018 at 10:33 AM.
01-24-2018, 09:08 AM
#218
Rennlist Member
This really pisses me off, we Canadians are always getting screwed.
Anyhoo, thanks for letting me know. I have made an appointment with my dealer for this afternoon to have them inspect the exhaust for debris and inquire why I wasn't informed of this potential issue when purchasing the car.
I suspect this will cost me a small fortune but for peace of mind...
Thanks again, this forum is truly a godsend.
Anyhoo, thanks for letting me know. I have made an appointment with my dealer for this afternoon to have them inspect the exhaust for debris and inquire why I wasn't informed of this potential issue when purchasing the car.
I suspect this will cost me a small fortune but for peace of mind...
Thanks again, this forum is truly a godsend.
01-25-2018, 08:58 AM
#219
Burning Brakes
I don't think this is a carbon build up issue on the intake valves. I've had the stumble since day zero. Although I have a 981, it is the same 9A1 engine in the 991.1 Base model and the 991.1 S model which all share a similar symptom. Whatever the problem is, it is common to those platforms. (i.e. 3.4 and 3.8 L engines.)
01-27-2018, 07:50 PM
#221
Rennlist Member
03-04-2018, 08:23 PM
#222
Addict
Rennlist Member
Rennlist Member
I plan to install the Softronic software this week. I’ll let you know my experience, weather permitting. I’m told we have another NorEaster headed our way.
Last edited by Scott MacDonald; 03-04-2018 at 08:44 PM.
03-05-2018, 07:33 AM
#224
Addict
Rennlist Member
Rennlist Member
I installed the Softronic software in my 996 turbo and had many trouble free years of road and track fun, with a significant improvement in torque and power.
If the dealer and Porsche don’t have a solution, why not try a different software map? It’s easy enough to reset to the factory settings.
If the dealer and Porsche don’t have a solution, why not try a different software map? It’s easy enough to reset to the factory settings.
03-07-2018, 11:54 PM
#225
I actually installed Cobb OTC mapping, the stumble is actually more noticeable. As the car pulling harder and faster, then all the sudden hit that stumbles in certain RPM, and then pulls again.
