Next Level Performance
August 5, 2026 • 11 min read
Upgrading the exhaust on a Porsche 911 Carrera (991) is the quickest, most rewarding way to unlock the flat-six's voice, drop unsprung factory weight, and — on the naturally aspirated cars — free up real horsepower. A Porsche 911 Carrera (991) exhaust upgrade is an aftermarket muffler, cat-back, or valved system engineered for the 2012–2019 991-generation 911 that reduces weight, sharpens throttle response, and amplifies the boxer engine's sound. At our Tampa, FL shop we install these systems every week, and the four below are the ones we recommend most often.
Our Verdict
For a 991.2 Carrera, the Akrapovic Slip-On Line (Titanium) is the best all-around exhaust — the deepest flat-six tone with roughly 8 lbs of weight savings and no tune required.
On a budget or running a naturally aspirated 991.1 3.8L? The aFe MACHForce XP cat-back adds a dyno-verified 34 hp and 43 lb-ft while shaving 20 lbs, for about half the price. Below we compare all four systems by sound, power, weight, fitment, and price.
Shop Our Top Pick →Why Upgrade the Porsche 911 Carrera (991) Exhaust?
The 991 splits into two very different engines, and that split decides which exhaust you should buy. The 991.1 (2012–2016) uses a naturally aspirated flat-six: the base Carrera runs a 3.4L making 350 hp, while the Carrera S and GTS use a 3.8L making 400 hp and 430 hp respectively. The 991.2 (2016–2019) switched to a twin-turbocharged 3.0L flat-six — 370 hp in the Carrera, 420 hp in the Carrera S, and 450 hp in the GTS.
That difference matters. On the naturally aspirated 991.1, a free-flowing cat-back can add a genuine 30–35 hp because the stock system is a real restriction. On the turbocharged 991.2, the turbochargers already scavenge and muffle the exhaust, so aftermarket systems add only a few horsepower — but they transform the sound, restoring the deep, hard-edged flat-six howl the turbos quiet down. Weight is the other win: factory 911 mufflers are heavy stainless units, and a titanium slip-on can cut roughly 8–9 lbs off the very back of the car.
Whether you are chasing sound, power, weight, or all three, matching the system to your exact 991 sub-generation and trim is the key. Below we break down the best options we stock, from a $7,070 titanium Akrapovic system to a $1,606 muffler bypass. In practice, most 991.2 owners come to us wanting the sound their turbocharged car lost from the factory, while 991.1 owners are usually chasing the naturally aspirated horsepower and the raw, high-rpm scream that only a freer exhaust delivers.
Akrapovic titanium mufflers for the 991.2 Carrera S/4/4S/GTS.
Best Porsche 911 Carrera (991) Exhaust Systems Compared
Here are the four 991 Carrera exhaust systems we recommend most, ordered from the flagship titanium slip-on down to the budget muffler bypass. Each is a verified, in-stock fit for a specific 991 sub-generation.
1. Akrapovic Slip-On Line (Titanium) — Best Overall for 991.2
The Akrapovic Slip-On Line is our top pick for the turbocharged 991.2 Carrera. It replaces the heavy factory rear mufflers with hand-built titanium units and titanium tailpipe tips, cutting roughly 8–9 lbs while giving the 3.0L twin-turbo flat-six a noticeably deeper, motorsport-grade tone. Because it is a slip-on, it retains the factory catalytic converters — so it bolts on with no tune, keeps your factory sound-valve behavior on PSE (Porsche Sport Exhaust) cars, and stays street-friendly.
Key Specifications — Akrapovic Slip-On Line
What We Like
- + Hand-welded titanium construction is dramatically lighter than the stock mufflers
- + Deep, refined flat-six tone that wakes up the quiet 991.2
- + Slip-on design retains factory cats — no tune, emissions-friendly
Things to Consider
- – Flagship pricing at $7,070.25
- – Slip-on adds sound and weight savings, not big power
2. AWE Tuning SwitchPath — Best Valved Exhaust for 991.2
If you want a car that whispers on the highway and screams at wide-open throttle, the AWE SwitchPath is the answer. It is a full valved cat-back for PSE-equipped 991.2 Carrera and Carrera S models: electronically controlled valves toggle between a quiet touring path and a loud performance path, tied into the factory sport-exhaust button. AWE's 180 Technology targets and cancels cabin drone at cruise, so you get the volume without the headache on a long drive. The Diamond Black tips add a stealth look. AWE backs it with a lifetime exhaust warranty.
What We Like
- + Switchable quiet touring and loud performance modes on demand
- + 180 Technology drone-cancellation keeps highway cruising civil
- + Integrates with the factory PSE button; backed by a lifetime warranty
Things to Consider
- – Only for PSE-equipped 991.2 cars
- – A full cat-back install is more involved than a slip-on
AWE SwitchPath valved cat-back with Diamond Black tips.
3. aFe MACHForce XP Cat-Back — Best Power Value for 991.1
For the naturally aspirated 991.1 3.8L, the aFe MACHForce XP is the best power-per-dollar system we sell. aFe's own dyno testing shows this dual cat-back producing 34 additional horsepower and 43 lb-ft of torque while weighing 20 lbs less than the stock exhaust. It is built from mandrel-bent SS-304 stainless with dual carbon fiber tips, and it uncorks the 3.8L flat-six into a proper naturally aspirated wail. Note: this system is not CARB-legal and cannot ship to California.
What We Like
- + Dyno-verified +34 hp and +43 lb-ft on the NA 3.8L
- + 20 lbs lighter than stock, in durable SS-304 stainless
- + Carbon fiber tips and aggressive naturally aspirated tone for $3,596
Things to Consider
- – 991.1 3.8L only — not for the turbo 991.2
- – Not CARB-legal; will not ship to California
aFe MACHForce XP SS-304 cat-back — +34 hp on the NA 3.8L.
4. aFe MACHForce XP Muffler Bypass — Best Budget Sound
Want more flow and volume from your 991.1 C2S without spending five figures? The aFe MACHForce XP muffler bypass replaces the restrictive secondary mufflers with 2.5in mandrel-bent stainless pipes. At $1,606 it is the cheapest way into a louder, freer-breathing 911 — it lets the 3.8L's note through, especially past 4,000 rpm, and pairs well with a high-flow intake. Like the cat-back, it is not CARB-legal for California.
What We Like
- + Lowest-cost path to more exhaust flow and sound at $1,606
- + 2.5in mandrel-bent stainless secondary bypass pipes
- + Great pairing with a cold-air intake on the 991.1 C2S
Things to Consider
- – Adds sound and flow, minimal peak power on its own
- – Not CARB-legal; 2012–2014 C2S fitment only
2.5in stainless muffler bypass — the budget path to more sound.
Porsche 911 Carrera (991) Exhaust Comparison Table
| Kit | Type | Fits | Key Benefit | Price |
|---|---|---|---|---|
| Akrapovic Slip-On Line (Ti)Top Pick | Titanium Slip-On | 991.2 (2016–2017) | Lightest, deepest tone | $7,070.25 |
| AWE Tuning SwitchPath | Valved Cat-Back | 991.2 (2017–2020) | Quiet/loud on demand | $4,935.00 |
| aFe MACHForce XP Cat-Back | Cat-Back | 991.1 3.8L (2012–2016) | +34 hp / +43 lb-ft | $3,596.00 |
| aFe MACHForce XP Muffler Bypass | Muffler Bypass | 991.1 C2S (2012–2014) | Budget sound & flow | $1,606.00 |
Slip-On vs Cat-Back vs Muffler Bypass: Which 991 Exhaust Type?
A slip-on replaces only the rear mufflers and retains the factory catalytic converters and mid-pipes. It is the easiest install (about 1–2 hours), keeps emissions hardware intact, and is the go-to for the turbo 991.2 where the goal is sound and weight rather than power. The Akrapovic Slip-On Line is the benchmark here.
Akrapovic titanium tips — a slip-on retains the factory cats.
A cat-back replaces everything from the catalytic converters rearward — mid-pipes, resonators, and mufflers. It flows more and, on the naturally aspirated 991.1, that extra flow is worth real power (the aFe MACHForce XP's +34 hp). A valved cat-back like the AWE SwitchPath layers on switchable volume. Plan on roughly 2–3 hours to install.
A muffler bypass deletes just the secondary mufflers using straight pipes. It is the cheapest route to more sound and flow, ideal for a 991.1 owner who wants a louder car on a budget. It adds minimal peak power alone but pairs well with intake and tune upgrades.
Installation, Fitment & CARB Notes
Fitment is everything on the 991. The Akrapovic and AWE systems here are built for the turbo 991.2, while both aFe systems fit the naturally aspirated 991.1 3.8L — they are not interchangeable, so confirm your model year and whether your car is PSE-equipped before ordering. The AWE SwitchPath specifically requires a factory PSE (Porsche Sport Exhaust) car to use its valve integration.
In our Tampa, FL shop, a slip-on install runs about 1–2 hours and a full cat-back about 2–3 hours on a lift. None of these systems require an ECU tune to run safely. One important compliance note: both aFe systems (the MACHForce XP cat-back and the muffler bypass) are not CARB-legal and cannot ship to California addresses. The Akrapovic slip-on retains the factory catalytic converters, which keeps it the most emissions-friendly of the group. If you are unsure which system fits your exact 991, our team can verify your VIN before you buy. We always recommend confirming both your build date and your PSE status against the specific system, because a 991.2 slip-on will not bolt to a 991.1, and an aFe 991.1 cat-back will not fit the turbo car — ordering by generation alone is the most common mistake we correct.
Frequently Asked Questions
What is the best exhaust for a Porsche 911 Carrera (991)?
The best exhaust for a 991.2 Carrera is the Akrapovic Slip-On Line (Titanium) at $7,070.25 — it delivers the deepest tone and roughly 8–9 lbs of weight savings with no tune. For the naturally aspirated 991.1 3.8L, the aFe MACHForce XP cat-back is the best value, adding a dyno-verified 34 hp and 43 lb-ft for $3,596.
How much horsepower does a 991 Carrera exhaust add?
On the naturally aspirated 991.1 3.8L, a cat-back like the aFe MACHForce XP adds about 34 horsepower and 43 lb-ft of torque. On the twin-turbo 991.2, aftermarket slip-on and valved exhausts add only a few horsepower because the turbos already scavenge the exhaust — their real benefit is sound and weight reduction.
Does a 991.2 Carrera exhaust require a tune?
No. Slip-on and cat-back exhausts for the 991 are bolt-on and do not require an ECU tune to run safely. A tune can add power on the turbocharged 991.2, but the exhaust itself installs and functions without one.
Will an aftermarket exhaust void my Porsche 911 warranty?
No. Under the U.S. Magnuson-Moss Warranty Act, installing an aftermarket exhaust does not automatically void your factory warranty; a dealer must prove the part caused a specific failure. Note that the aFe systems are not CARB-legal and cannot be sold or shipped to California.
Slip-on vs cat-back for the 991 — which should I choose?
Choose a slip-on if you want the easiest install, retained factory catalytic converters, and mainly a better sound and lighter weight — ideal for the turbo 991.2. Choose a cat-back if you want maximum flow and, on the naturally aspirated 991.1, real horsepower gains from replacing everything behind the cats.
Do these 991 exhausts drone on the highway?
The AWE SwitchPath is the best choice to avoid drone: its 180 Technology cancels cruising resonance and its quiet mode keeps highway trips civil. The Akrapovic slip-on has a refined, deep tone, while the aFe cat-back and muffler bypass are louder and more aggressive by design.
How long does it take to install a 991 Carrera exhaust?
At our Tampa, FL shop a 991 slip-on install takes about 1–2 hours, and a full cat-back or valved system takes about 2–3 hours on a lift. No tuning is required, so the car is ready to drive as soon as the install is complete.
Ready to Wake Up Your 911 Carrera?
Shop titanium slip-ons, valved cat-backs, and more performance exhausts for the Porsche 911 at NLP Performance.
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