hey guys,

so ive ran into a little problem and I’m looking for help..

I ordered the Cobb Tune AP for my 2017 911 Carrera. I had in on the car for roughly 3 weeks with no issues. Then all of a sudden I noticed a lack of power with both stage 1 maps and the factory tune. I sent data logs to Aaron at Cobb Tuning and he also stated it was slightly degraded in power overall. Anybody with these tunes knows it’s night and day difference in power between factory and tuned. So, at this point I uninstalled the tune, and brought it in to Porsche to diagnose, now keep in mind even uninstalled I was only reaching around 8-9 psi boost where factory is around 13psi. They diagnosed it, and later told me it was ready to be picked up, I found out that they replaced the ECU under warranty stating that it had a faulty circuit and they also noticed it was reflashed but did not care. During the drive home from Porsche, it was reaching full factory boost so I figured everything was fixed...

I called up Cobb and sent the new ECU out to get unlocked again, I reinstalled the new ECU and flashed the stage 1 91 octane map, long behold it’s only reaching around 15 psi, spools faster but doesn’t overall feel much faster than factory tune, so what’s your guys thoughts? What should I look for next? I believe there is a weak link in the turbo/intercooler system. Is anyone else having issues? I can’t be the only one out there experiencing any type of issue

thanks guys!

I guess another tuning company could be better and sometimes the grass is greener. I can’t complain with the customer service I’ve had so far with Cobb, Aaron has been extremely helpful but I think this is beyond an ECU/Tune issue. I believe it is an actual failed component but I do not have any check engine lights which leads me to either turbo, intercooler, piping or one of the various lines throughout the system either faulty or leaking. A simple boost leak test could show a lot but what I’m stumped by is the fact that it was running low boost on the way to the dealer, then after they replaced the ECU it was acting perfectly normal. Now with the flash it’s spooling faster but not nearly sending the boost it did before any of this happened.

I have the Cobb tune in my TTS along with the PDK update. Love the tune and found Cobb very responsive to questions and issues. No CELS no issues.
Sorry to hear you are having these issues. If the tune is working properly your car should feel much quicker.

well that’s what I was thinking too.. but why would it act like a boost leak with the stock ECU, then when Porsche replaced the ecu it went back to normal 13 psi boost?

so it acted fine on the way home after the ecu was swapped out. I sent the ecu out to cobb to be unlocked again and when I reflashed it, it is not hitting target boost or anywhere close for that matter. More boost from the tune. Correct me if I’m wrong but I believe target boost is around 24 psi with stage 1? Right now I’m barely reaching 15psi

on datalog I was reaching upwards of 40 so subtracting the 14.7 so roughly 25 psi.

no smoke, no rough idle, I was running Mobil 93 with 2 gallons 100 octane. Mpg was low but I thought that was just the tune ~16mpg average.

I can’t believe you tuned a replacement DME.

That’s exactly what my wife said I can’t help myself!