Hello Rennlist,

Thank you all for the feedback and responses here. Getting a publicly posted thread like this with a competitor’s email cc’d to our company is hard to see. At the end of the day we want all of our partners and clients happy with the results and products they received. I’m glad to hear the OP’s case is resolved and he is happy with his calibration.

To address the specific issues we will start here.

There is an active TSB from Porsche, specifically for injectors on the 992 platform. The 992 piezo style injectors are prone to failure and have occurred on stock cars, cars with zero miles, tuned cars, low mile cars, you name it, we have seen it all. The majority of cars do not have this problem, but there have been enough cases of this which is why there is literally a Porsche service bulletin for it. The issue with injectors is exacerbated when tuning is applied where more commanded fuel and load requests are given. The injector open time is increased to meet the demand of fuel needed to safely run the car. The 992 platform also does not always throw faults for this, although sometimes they do. We specifically mention this issue in our map notes as seen here:

“NOTE ABOUT INJECTORS: Although very uncommon, the 992 platform (Carrera and Turbo) have a factory TSB for injector failures. The failure symptoms show themselves as an injector fault normally followed with misfiring under load. These symptoms can become exacerbated with tuning. If your car has any injector problems, it’s important to get this repaired. This normally requires injector replacement and reprogramming. “


From the factory, Porsche’s wide open throttle fueling strategy targets a very lean lambda target of 1. This is to meet emissions criteria. To increase power, added fuel is needed to match the new increased mass of air entering the engine. What is done on the calibration side is an increase of injector open time. With finicky or issue injectors, this can cause issues with misfiring and poor driving and performance. This is why in this person’s case, the Stage 0 mapping we sent them worked fine. It required less injector open time and commanded a much lower load.

So why is it working on a competitor’s flash you might ask? This is simple. Stage 0 files can be reworked to increase boost levels to command more power, but keep the lean running condition of a lambda of 1 or close to 1 at WOT. In the long run, this is harmful to an engine if not managed properly. It also won’t be a very powerful or fast calibration either. We are very transparent about our calibrations and offer our own in-house flashing protocol and the ability to datalog with M-Tuner. With some of these other files out there, you are not given that ability. You cannot see what the engine is doing. It is a smoke and mirrors case of running a factory file with just some added load targets. How do you know it is running a safe AFR? How do you know the knock thresholds are not removed? How do you know what requested load and load actual are doing? How do you know how much manifold pressure you are running? How do you know how much ignition timing the car is running? You don’t.

Attached here is a photo of a lambda target table using our in-house software, M-Composer. The top is stock from Porsche, with commanded targets of lambda of 1, compared to a tune file (bottom) with richer targets to match for a well running combustion cycle.




Overtime, the injector issue will become worse and show its face even in the stock form if your car is showing these symptoms. This is not something to overlook. What may start as a simple misfire that can be resolved with a hardparts replacement can eventually turn into damaged engine components. A 992 block sure sounds like a pricey replacement.

This owner’s particular car is ROM ID 992906021CE, a very common box code with vetted calibrations on several dozen cars of this exact ID. If this were a tuning issue on our end, our other customers with this same ROM ID would be making this same complaint, as the base file we made for these is going to be the same byte for byte.


I’ve attached a Porsche TSB for the injector fault. Normally, Porsche replaces the injectors under warranty along with the harness for it. The injectors should always be replaced as a full set of 6 as they are flow tested and manufactured in batches. They also have to be specifically programmed to the car. Here is also an example of another thread on RL of owners seeing this on stock cars (this issue is present on Carrera and Turbo btw): https://rennlist.com/forums/992-turb...workshopn.html

We proudly stand by our products and helping customers out in every situation we can. If your car has a mechanical problem we can see through empirical data we will always let you know. We will not be responding to this thread any further.

M-Engineering