Mazda MX-5 Miata Cat-Back Exhaust Install Guide (NA-ND)

Installing a cat-back exhaust on your Mazda MX-5 Miata is one of the cheapest, most satisfying upgrades you can make — a bolt-on job that takes about an hour, wakes up the four-cylinder note, and trims a few pounds off the tail of an already featherweight roadster. This guide walks through exactly how to install a Miata cat-back exhaust on every generation from the 1990 NA to the current ND, which system fits your car, the tools and torque figures you need, and the five stainless-steel kits we stock at NLP Performance in Tampa, FL, that range from roughly $570 to $1,130.

What Does a Cat-Back Exhaust Do on a Miata?

A cat-back exhaust replaces every component from the catalytic converter back — the mid-pipe, muffler, and tips — while leaving the factory cat in place. Because the emissions hardware is untouched, a cat-back is street-legal in all 50 states and does not throw a check-engine light. On a light car like the Miata, the payoff is threefold: a freer-flowing, mandrel-bent path that reduces backpressure, a noticeably richer exhaust note, and a small weight reduction over the heavier OE muffler.

Be realistic about power. The Miata's naturally aspirated engines — the 1.6L and 1.8L in the NA/NB, the 2.0L MZR in the NC, and the 2.0L Skyactiv in the ND — are small-displacement units, so a cat-back alone typically frees up roughly 3 to 8 wheel horsepower depending on generation and whether it is paired with an intake and tune. The real reasons owners install one are sound and weight: mandrel-bent T304 stainless systems shed pounds versus a rusting OE unit and transform a muted factory drone into the raspy, mechanical bark the chassis deserves. At our Tampa shop, cat-backs are the single most requested Miata upgrade precisely because the character change is so dramatic for the money.

Which Cat-Back Fits Your Miata Generation?

Miata exhausts are generation-specific — a system for the NA will not bolt to an ND, so identify your chassis code first. There have been four generations across 34 model years, and each uses a different mid-pipe length, hanger layout, and rear valance cutout. Here is how the systems we carry line up:

NA (1990-1997) — 1.6L & 1.8L

The original pop-up-headlight roadster takes the Borla 90-97 cat-back, a T304 stainless system that clamps to the factory mid-pipe location and exits with Borla's signature straight-through muffler. It fits both the 1.6L (1990-1993) and 1.8L (1994-1997) cars.

NB (1999-2005) — 1.8L

The second-generation NB uses the MagnaFlow 99-05 cat-back, a stainless straight-through design tuned for the 1.8L. It bolts up to base, LS, and SE trims and keeps the factory hanger geometry so no fabrication is required.

NC (2006-2015) — 2.0L MZR

The larger NC (the first Miata with a 2.0L) has two strong options: the Borla 06-14 twin-tip cat-back and the MagnaFlow 06-onward system. Both are full cat-backs for the RWD 2.0L and give the NC a deeper, more aggressive tone than the softer factory unit.

ND (2016-2024) — 2.0L Skyactiv

The current ND is the most flexible: run the MagnaFlow 15-16 full cat-back for the maximum flow and volume change, or step into the Revel Medallion Touring-S axle-back for a bolt-on-in-30-minutes upgrade that keeps cost down. Both use dual-tip rear exits sized for the ND's twin cutout.

The 5 Miata Cat-Back Systems We Stock

Every kit below is mandrel-bent stainless steel, ships with the required clamps and gaskets, and is a direct bolt-on to its listed generation. Prices shown are live and update automatically at checkout.

This is our top pick for ND owners. The dual pass-side rear-exit layout and 3-inch polished tips give the Skyactiv 2.0L a full-bodied growl without becoming unbearable at cruise, and the T304 stainless construction resists Florida's coastal corrosion far better than aluminized OE steel.

How to Install a Miata Cat-Back Exhaust: Step by Step

A Miata cat-back install takes about 1 to 1.5 hours with basic hand tools and no cutting or welding. The Revel axle-back can be done in roughly 30 minutes. The process is nearly identical across NA, NB, NC, and ND chassis because all four use bolted flanges and rubber hanger isolators. Work on a cold exhaust — components stay hot for 30+ minutes after driving.

Tools and Supplies You Will Need

Gather a floor jack and two jack stands (or ramps), a 12mm and 14mm socket plus ratchet, a set of combination wrenches, penetrating oil, an exhaust hanger removal tool or spray lubricant, anti-seize, and a torque wrench. New spring bolts or slip-fit clamps are included with each kit.

The 6-Step Install

1. Raise and support the car. Jack the rear evenly and set both jack stands under the factory lift points. Never work under a car held only by a jack.
2. Soak the fasteners. Spray penetrating oil on the cat-back flange bolts and let it sit 10 minutes — Miatas rust at the mid-pipe joint, especially in salt or coastal climates.
3. Support and unbolt the OE system. Support the muffler with a jack or a helper, remove the flange nuts at the catalytic converter, then free the rubber hangers with lubricant and a hanger tool.
4. Transfer hangers and gasket. Move any reusable rubber isolators to the new system's hanger rods and fit the supplied flange gasket.
5. Hang the new cat-back loosely. Slide the new system's hangers into the isolators and start every flange bolt by hand before tightening anything — this lets you align the tips squarely in the rear valance.
6. Torque and check clearance. Tighten the flange bolts (typically 25-35 ft-lb) and clamps, confirm at least a finger's width of clearance around the tunnel and rear subframe, then start the car and check for leaks and tip alignment.

Miata Cat-Back Comparison Chart

Here is how the five systems compare by generation fitment, configuration, and price. Every product name and price links directly to its page.

MagnaFlow ND Cat-Back: Pros and Cons

Sound, Weight, and What to Pair With Your Cat-Back

A stainless cat-back changes the Miata's character more than any single mod under $1,200. The factory MX-5 muffler is a heavy, restrictive chambered unit tuned for showroom quiet; swapping to a mandrel-bent straight-through system opens up a raspy four-cylinder rasp that builds into a genuine snarl past 4,000 rpm. Because T304 stainless is thinner and lighter than the double-walled aluminized OE muffler, most owners also drop a few pounds at the very back of the car — useful mass to lose on a chassis that already weighs only about 2,100 lbs (NA) to 2,340 lbs (ND).

To turn that sound into measurable power, pair the exhaust with the two mods that complement it. A cold-air or short-ram intake feeds the freer-flowing exhaust and, on the NC and ND 2.0L, the combination plus a tune commonly nets into the low double digits of wheel horsepower — far more than the exhaust alone. On turbocharged Miata builds, a cat-back becomes even more valuable because it clears the post-turbo restriction that limits spool and top-end flow. If your goal is purely a better soundtrack, run the exhaust by itself; if you want the numbers, budget for an intake and a reflash at the same time so the ECU can take advantage of the extra flow.

One practical note from our Tampa install bay: always inspect the rubber hanger isolators when the old system is off. Cracked or oil-soaked isolators let the new exhaust rattle against the tunnel, and replacing a $10 hanger during the install saves an annoying drive-home buzz. It is the cheapest insurance on the whole job.