Mercedes-AMG E63 W213 Exhaust Upgrade: 2018-2023 How-To

A Mercedes-AMG E63 (W213) exhaust upgrade is a cat-back replacement for the 2018–2023 E63 and E63 S 4MATIC+, and the single most important thing to know before you buy one is this: your part number depends on whether your car left the factory with the optional AMG Performance Exhaust. Get that wrong and the kit will not bolt up correctly. The 603-hp, 627 lb-ft M177 4.0L twin-turbo V8 under the hood is one of the great modern V8s, and it responds to an exhaust with sound and weight loss far more than it does with horsepower. This guide walks through the 30-second under-car check that tells you which system to order, compares the Akrapovic Evolution Line titanium system against the AWE Tuning SwitchPath, and covers the full install — torque specs, gotchas, and all.

Step 0: Does Your E63 Have the AMG Performance Exhaust?

To tell whether a W213 E63 has the AMG Performance Exhaust, look under the car for a factory exhaust valve on the front crossover tube, just behind the transmission. If a valve and its actuator motor are sitting there, your car has the option. If the crossover tube is plain pipe, it does not. That is the entire check, and it takes about 30 seconds with the car on a lift or on ramps. AWE Tuning documents this exact identification method in its official W213 install guide, and it is the reason the company sells two different part numbers for the same car.

This matters because the AMG Performance Exhaust was an option on the W213 E63, not standard equipment. It adds electrically actuated valves that open and close with the drive mode — quiet in Comfort, with the crackle and overrun pops arriving in Sport+ and Race. Cars built without it are quieter, are harder to resell, and require a completely different aftermarket kit. Owners typically report the option cost somewhere in the $1,250–$1,700 range when the car was new.

At our Tampa shop we do this check before we quote any E63 exhaust job, because the wrong part number is a wasted freight run on a 60-pound stainless or titanium system. Do it before you click buy.

APE, DPE, Performance Exhaust: Decoding the Names

APE and DPE are the same thing: the factory AMG Performance Exhaust option on the W213 E63. AWE Tuning's own installation guide calls it the AMG Performance Exhaust (APE). Many resellers list the identical kit as being "for DPE cars," using Dynamic Performance Exhaust as shorthand. There is no third system and no functional difference — only vendor vocabulary. When you see a listing "for DPE cars," read it as "for cars that already have the factory valved exhaust."

Two part numbers follow directly from that: AWE 3025-31044 is the SwitchPath for cars with the factory performance exhaust, and 3025-31046 is for cars without it. The non-APE kit actually costs more ($4,725 MSRP versus $4,315) because it has to add valve hardware and a remote-control kit the car never had from the factory.

How Much Horsepower Does an E63 Cat-Back Actually Add?

A cat-back exhaust on a W213 E63 is a sound-and-weight modification, not a power modification — expect near-zero to modest single-digit wheel horsepower, not the 20–35 hp printed on product pages. Those larger figures are manufacturer crank-horsepower claims. Akrapovic states +15.1 kW (about 20.2 hp) and +54.4 Nm (about 40.1 lb-ft), but reads the fine print: those are gains measured at a single point, 2,550 rpm, not peak-to-peak. AWE claims +23 hp peak and up to +35 hp at 6,300 rpm at the crank. We have not found an independent back-to-back dyno of a cat-back-only W213, and we are not going to pretend otherwise.

The engineering reason is simple. The M177 is a hot-V twin-turbo engine: two BorgWarner turbochargers sit inside the vee, and the factory catalytic converters and downpipes are the real restriction. A cat-back lives entirely downstream of the cats, so it is working on gas that has already passed through every meaningful flow bottleneck.

Where the power actually lives is downpipes plus a tune. One third-party dyno of a W213 E63 S recorded 527 whp / 616 lb-ft on catless downpipes, rising to 598 whp / 763 lb-ft with a Stage 2 pump-gas ECU tune, measured at all four wheels. That is a real 71 wheel-horsepower swing. Be aware: catless downpipes are not 50-state legal and are sold for closed-course use only. A cat-back is the legal, warranty-safe half of that equation.

Akrapovic Evolution Line vs AWE SwitchPath: Which W213 Exhaust Should You Buy?

Buy the Akrapovic Evolution Line if your E63 has the factory AMG Performance Exhaust and you want titanium, carbon tips, and 13.6 kg (about 30 lb) less weight; buy the AWE SwitchPath if you want the same valve control for roughly half the money, a lifetime warranty, or if your car does not have the factory valve system at all. Those are genuinely the two questions that decide this purchase.

Akrapovic Evolution Line Titanium: The Complete System

This is the all-in-one listing: the Evolution Line titanium cat-back, the titanium link pipe set, and the hand-made high-gloss carbon fiber tail pipes together. That bundling matters, because Akrapovic sells the three pieces separately and all three are mandatory to complete the system — a fact that catches out plenty of buyers who order the cat-back alone and then discover they cannot finish the job. The system uses an active X-connection plus an additional pair of exhaust valves behind the rear mufflers, and it is engineered to replace the AMG Performance Exhaust, which is why the factory option is a hard prerequisite. It also does not fit cars equipped with a gasoline particulate filter (OPF/GPF), which in practice means it is aimed at US-market cars rather than European ones.

Akrapovic Evolution Line Cat-Back (Without Tips)

Buy this only if you are also buying the link pipes and tips — or if you already own a set. It is the same titanium system as the bundle above, listed on its own for buyers who want to specify a different tip finish. Budget accordingly: cat-back plus link pipes plus tips lands within a few hundred dollars of the complete kit, so the bundle is usually the cleaner purchase.

The Two Mandatory Companion Parts

AWE Tuning SwitchPath: The Value Play

The SwitchPath is built from dual 3-inch (76.2 mm) .065-inch-wall CNC mandrel-bent T304L stainless steel, and it gives you two axes of control rather than one: the valved H-pipe up front shapes the tone, and the valved rear sections control the volume. On APE cars — part number 3025-31044, the one we stock — you transfer the factory valve control motors onto the AWE H-pipe and rear sections, so the exhaust keeps responding to Comfort, Sport, Sport+ and Race exactly as it did from the factory. No tune, no check-engine light, 50-state legal, and AWE backs it for life. The trade-off is that the kit reuses your factory exhaust tips and bezels, so the car looks completely stock from behind.

How to Install a Cat-Back Exhaust on a W213 E63: Step by Step

A W213 E63 cat-back install takes roughly 4–6 hours on a two-post lift with two people, and the only torque figure the manufacturer publishes is 40 ft-lb minimum on the 3-inch Accu-Seal and factory olive clamps. The OEM exhaust comes out as one heavy piece, so a second set of hands or a pole jack is not optional. Here is the sequence, drawn from AWE's official install guide (Rev 1.1).

1. Confirm your car's configuration. Check the front crossover tube behind the transmission for the factory valve. APE car or non-APE car — this determines the kit you should already have in hand.
2. Soak the olive clamps in penetrating oil. They seize. Do this first and let it work while you set up.
3. Disconnect the valve motor harnesses. Pull the slide lock out, then squeeze the connector to release. On APE cars, also unplug the H-pipe valve connector ahead of the crossover. Snapping one of these connectors is the most expensive five seconds of the job.
4. Drop the underbody panels. Remove the two panels along the driveshaft tunnel (10 mm plastic nuts, 8 mm screws), the rear tray, and the diagonal chassis cross-braces. The system will not come out otherwise.
5. Free the exhaust tips. Loosen the two Torx screws per side and slide each tip bezel rearward. Skip this and the system will not clear the bumper.
6. Support the exhaust and drop it. Pole jack or second person. Work the rear hangers out of the rubber mounts — penetrating oil helps here too.
7. Transfer the factory valve motors. They are not included in any kit. Move them from the OEM mufflers onto the new rear sections, and on APE cars, from the OEM crossover onto the new valved H-pipe.
8. Hang the new system front to back. Inlet tubes, H-pipe, axle tubes, then rear sections — seating each rear outlet into the tip bezel area first, then connecting forward to the axle tubes.
9. Do not torque anything yet. Hang the entire system, then adjust for alignment and clearance. Verify a minimum 1/2-inch gap between the exhaust and all heat shielding; that gap exists so the system can expand without rattling or scorching.
10. Torque from the front, working rearward. Accu-Seal clamps and factory olive clamps get a minimum of 40 ft-lb. Plastic underbody hardware gets snug only — over-torque it and you will strip it. For OEM fasteners, use the Mercedes service manual values.
11. Install the exhaust brace last, reinstall the cross-braces and panels, reconnect the valve harnesses, and reinstall the tip bezels.
12. Start it, cycle the drive modes, and confirm the valves actuate in Sport+ and Race. Then check for leaks and re-verify heat shield clearance once everything has been through a heat cycle.

In our experience the seized olive clamps are the single most common source of delay on this job, which is why they get penetrating oil before anything else comes apart — and why we tell customers booking an E63 exhaust install in Tampa to plan for the back half of a day, not a lunch break. Tools: Torx bits, 8 mm and 10 mm sockets, standard metric ratchets, penetrating oil, a torque wrench that reaches 40 ft-lb, and a pole jack. Shop labor on a job like this typically runs 4–5 hours in the $400–$500 range. If you are running the non-APE AWE kit (3025-31046), add time for the SwitchPath Remote control box and harness, which ship with their own separate instructions.

Parts to Order With Your E63 Exhaust

Since the car is already on the lift and the underbody is open, these are the jobs worth stacking onto the same appointment.

The Goodridge stainless braided brake hose kit ($157.91) is the cheapest meaningful pedal-feel upgrade on a car that weighs roughly 4,500 lb and makes 603 hp; braided lines resist the expansion that makes rubber hoses feel soft when hot. DFC drilled and slotted rear rotors ($101.54) are a sensible replacement at pad-change time, and the K&N drop-in replacement air filter ($131.45) is a washable, reusable panel filter that drops straight into the factory airbox. For the small number of customers going all the way — forged internals for a big-power build — we also stock the CP forged piston set for the M177/M178 ($1,709.89) in the factory 83 mm bore.

Warranty, Emissions and Noise Laws

Under the federal Magnuson-Moss Warranty Act, Mercedes-Benz cannot void your factory warranty simply because you installed an aftermarket exhaust — the burden is on the dealer to prove the part caused the specific failure being claimed. That protection is real, and a cat-back is the lowest-risk modification on the list: it does not touch the ECU, the catalytic converters, or any emissions sensor. It is also, by definition, downstream of the cats, which is why cat-back systems do not require a CARB Executive Order number and are generally 50-state legal. AWE markets its W213 systems explicitly as 50-state legal with no emissions tampering.

Two honest caveats. First, Magnuson-Moss protects you legally but does not stop a dealer from denying a claim and making you fight it — and the risk profile changes completely once you add catless downpipes and a tune, which is where real powertrain warranty disputes happen. Second, the meaningful legal exposure on a cat-back is noise, not emissions: state and local sound ordinances still apply, and a valved system that can be opened up is your friend here.