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Porsche 997: Why is My Car Losing Power?

Less of something is never a good thing, but less power is quite possibly the worst thing to happen to a Porsche 997/911. Find out what could be causing this problem.

By Jerry Perez - May 4, 2015

This article applies to the Porsche 997/911 (2005-2012).

Imagine you are at a stop light, and as the green light comes on you want a slight reminder of why you bought a Porsche to begin with. But what you get, instead of a big surge of power, is a muted engine and lack of acceleration. Definitely not a good thing. There are multiple scenarios that could be causing your engine to loose power, so here is compiled list of the common causes creating the decrease to no power in your Porsche 997/911.

Step 1 – Check spark plugs

They might be misfiring.

Brand new spark plugs and coil packs are set to be replaced during the 60,000 mile service, according to the Porsche maintenance schedule. But it has been reported that spark plugs and coils may go bad before that mark. Before you pull out the spark plugs, make sure the wires are secured to the plug, and they are attached properly to the coil packs. If there is a bad connection, then it could make your Porsche 997/911 have a sudden loss of power due to lack of voltage to the engine, especially at high revs when more power is needed.

Figure 1. Check spark plug wires and coil packs.

Step 2 – Check mass airflow sensor (MAF)

It might be faulty.

The mass airflow sensor (MAF) determines the mass or volume of air that is traveling through the intake body of your Porsche 997/911. This information is then relayed to the ECU, so it can determine the right amount of air and fuel mixture necessary for the engine to operate properly. So as you can see, any slight issue or variation in the MAF could throw off the entire system. You can first try removing it and plugging it back. If that doesn't work, try disconnecting the engine to let the system reset. If that still doesn't do it, then it must be replaced. A new sensor can cost from $200 to $300 without labor, but it is a simple DIY project.

Figure 2. Porsche MAF located on the air intake system.

Step 3 – Check throttle control

It could be sending the wrong signal.

Just like most components in your Porsche 997/911, the electronic throttle control tells the ECU how pressed or depressed the throttle pedal is; then, the computer will react accordingly in milliseconds for your driving enjoyment. If the throttle control is misfiring or not reading the correct position, it could tell the ECU you are at only 25% throttle when you are actually at 80% throttle. So the car will only react to what the throttle control and ECU relay. This is also known as drive by wire, and a new one can be purchased for around $400 for parts.

Figure 3. Drive by wire throttle system.

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