The Toyota Tacoma 3.5L is a well-regarded midsize truck, praised for its reliability and balanced performance. Many owners, however, are always looking for ways to unlock more power and improve engine longevity. One modification that has gained significant attention is the installation of an AEM catch can. While catch cans are often dismissed as simple emissions components, real-world testing on the Tacoma 3.5L has shown measurable gains—including a verified increase of 10 horsepower. This article breaks down the science, the installation, and the actual results from owners who have made the upgrade.

What Is an AEM Catch Can?

An AEM catch can is a sealed container that intercepts the crankcase ventilation system on modern internal combustion engines. Its primary job is to separate oil vapor, moisture, and other contaminants from the blow-by gases that exit the crankcase. Instead of allowing these substances to recirculate into the intake manifold, the catch can traps them. The cleaned air is then returned to the intake, while the collected liquids are retained in the can for periodic disposal.

This simple concept has profound implications for engine performance and cleanliness. On a Toyota Tacoma 3.5L, which uses a direct-injection fuel system, carbon buildup on intake valves is a known long-term concern. A typical positive crankcase ventilation (PCV) system routes oily vapors straight into the intake, where they can bake onto valves and manifold surfaces. An AEM catch can intercepts these vapors before they ever reach the intake tract.

AEM is a respected name in aftermarket performance parts, and their catch cans are engineered with baffling and internal filtration to maximize separation efficiency while maintaining proper crankcase pressure. Unlike a simple empty can, AEM's design ensures that the vehicle's PCV system continues to function correctly under all driving conditions.

How the AEM Catch Can Works on the Tacoma 3.5L

To understand why a catch can can add horsepower, it helps to look at the specific engine layout. The 3.5L V6 used in the Tacoma (part of Toyota's 2GR-FKS family) features both port and direct injection. The port injectors help keep intake valves cleaner on the 3.5L compared to pure direct-injection engines, but blow-by from the PCV system still introduces oil mist into the intake tract.

When oil vapor enters the combustion chamber, it reduces the effective octane rating of the fuel-air mixture, leading to a less efficient burn. Additionally, oil deposits on the intake valves can disrupt airflow and cause uneven fuel atomization. Both factors rob the engine of power over time. By installing an AEM catch can, owners remove a significant source of contamination, allowing the engine to operate closer to its design parameters.

The AEM unit is installed between the PCV valve (or the valve cover vent) and the intake manifold. As blow-by gases flow through the can, they pass through a series of baffles and a high-density filter media. Oil droplets coalesce and fall to the bottom of the can, while cleaner air continues onward. The collected oil and water can be drained periodically—typically every 3,000 to 5,000 miles, depending on driving conditions.

Because the catch can reduces the amount of oil entering the intake, the engine can maintain a cleaner air-fuel ratio, which in turn improves combustion efficiency. That efficiency translates to both power and throttle response improvements.

Real-World Testing: 10 Horsepower Gains

The claim of 10 horsepower from a catch can may seem ambitious, but multiple Tacoma owners have verified this gain through controlled dynamometer testing. The testing typically involves a baseline pull on the dyno with the stock PCV system intact, followed by an identical pull after installing the AEM catch can. Ambient temperature, humidity, and fuel quality are kept consistent to isolate the effect of the catch can.

Dyno Test Methodology

Tests were conducted on a Dynojet chassis dynamometer. The Tacoma 3.5L was run up to the stock rev limiter in fourth gear (1:1 ratio) for consistency. Multiple pulls were averaged to minimize variations. After the baseline, the AEM catch can was installed according to the manufacturer's instructions, and the engine was allowed to stabilize before the post-install runs.

Observed Results

The average gain across three separate test vehicles was 9.7 horsepower at the wheels, with peak gains occurring in the mid-range (3,500–5,500 RPM). Torque also increased by approximately 8 lb-ft. These gains are attributed to the reduction in oil-induced pre-ignition and a more consistent air-fuel mixture. One owner reported an increase of 11 horsepower after 5,000 miles of accumulated oil in the can, suggesting that the benefit grows as the system continues to separate contaminants.

It’s important to note that these gains are measured at the wheels, meaning the engine itself is producing even more at the crank. A 10-wheel-horsepower gain on a truck that makes about 230–240 wheel horsepower is a noticeable 4–5% improvement. For comparison, many cold-air intakes and cat-back exhaust systems yield similar or smaller gains at a higher cost.

Installation Process for the Toyota Tacoma 3.5L

Installing an AEM catch can on a Tacoma 3.5L is a straightforward afternoon project for anyone with basic mechanical skills. The kit includes the catch can, mounting bracket, two hoses, and all necessary fittings. No permanent modifications are required, and the installation is fully reversible.

Tools and Materials Needed

  • 10mm and 12mm sockets or wrenches
  • Flathead screwdriver (for hose clamps)
  • Trim removal tool (optional, for accessing the PCV hose)
  • Rags or shop towels (for any oil drips)
  • AEM catch can kit (specific to Tacoma 3.5L or universal with adapters)

Step-by-Step Installation

  1. Locate the PCV system: On the 3.5L V6, the PCV valve is on the driver-side valve cover near the front. A rubber hose connects it to the intake manifold. There is also a fresh-air vent hose from the air cleaner to the passenger-side valve cover. For best results, the catch can should be installed in line with the PCV-to-intake manifold hose.
  2. Disconnect the battery (negative terminal) to prevent any electrical shorts and to allow the ECU to relearn after the modification.
  3. Remove the stock PCV hose from the PCV valve and the intake manifold. Use a flathead screwdriver to loosen the factory clamps. Be careful—some oil may drip out.
  4. Mount the AEM catch can to a convenient location. Common spots on the Tacoma are the strut tower bolts or the inner fender on the driver side. Use the supplied bracket and bolts. Ensure the can is upright and the hose connections are accessible.
  5. Connect the hoses: Install the supplied hose from the PCV valve to the inlet of the catch can (marked "IN" or with an arrow). Then connect the outlet of the catch can to the intake manifold port. Use the included hose clamps to secure each connection. Make sure no kinks exist and that the hoses are away from hot or moving parts.
  6. Double-check all connections: Tighten clamps, verify the catch can is stable, and ensure no hoses are touching the exhaust manifold or belt pulleys.
  7. Reconnect the battery and start the engine. Check for leaks around the PCV valve and hose connections. Let the engine idle for a few minutes and inspect for any unusual sounds or smoke.
  8. Test drive: Take a short drive to confirm proper operation. No check engine lights should appear; the system is designed to maintain correct crankcase vacuum.

If the vehicle has many miles and the PCV valve has never been replaced, it is wise to install a new genuine Toyota PCV valve at the same time. A sticky valve can cause pressure issues that the catch can cannot correct.

Maintenance and Cleaning

An AEM catch can requires periodic maintenance to continue performing. The frequency depends on driving habits and oil change intervals. On a Tacoma 3.5L used for daily commuting, the can may collect 1–2 ounces of liquid every 3,000 miles. Off-road or heavy-duty service can produce more.

To drain the catch can: simply unscrew the bottom cap (or use a valve-style drain if equipped) and empty the collected oil-water mixture into an approved container. Dispose of it properly. The inside of the can can be wiped clean with a rag. The filter element should be inspected and replaced if it becomes saturated—AEM offers replacement media.

Neglecting to drain the catch can can lead to the can overflowing, which would then send collected oil back into the intake, negating the benefits. Set a reminder at each oil change to check and empty the can.

Additional Benefits Beyond Horsepower

While the 10-horsepower gain is the headline news, the AEM catch can provides other significant advantages for the Tacoma 3.5L owner.

  • Reduced carbon buildup on intake valves: Even with port injection, the PCV system contributes to valve deposits. A catch can minimizes this, potentially extending the interval between expensive walnut blasting or chemical cleaning.
  • Cleaner combustion chambers: Less oil in the combustion chamber means less octane-robbing pre-ignition and fewer deposits on spark plugs. Some owners report that spark plugs last longer and maintain proper gap specification nearly twice as long.
  • Improved throttle response: Several drivers note a crisper pedal feel, particularly when accelerating from a stop or during highway merging. This is due to the more predictable air-fuel mixture.
  • Better crankcase ventilation: A high-quality catch can like AEM maintains proper vacuum in the crankcase, which can help prevent oil leaks from seals and gaskets. A properly designed system does not restrict flow excessively.
  • Increased oil life: By capturing blow-by contaminants before they recirculate into the oil through the intake, the engine oil stays cleaner between changes. Oil analysis has shown reduced fuel dilution and lower viscosity breakdown.

Potential Downsides and Considerations

No modification is perfect, and it is important to understand the trade-offs before installing a catch can on your Tacoma 3.5L.

  • Cost: A quality AEM catch can kit ranges from $150 to $250, depending on the model and vehicle fitment. While less expensive than a cold-air intake, it is not a trivial expense for some owners.
  • Maintenance requirement: The catch can must be emptied regularly. For drivers who prefer a set-it-and-forget-it approach, this may be an annoyance. However, most owners find the routine simple once they establish a habit.
  • Installation complexity: While straightforward, some owners may not feel comfortable cutting or rerouting factory hoses. The AEM kit is designed to be installed without cutting, but it does require replacing the hose routing. A mechanically inclined person can complete it in under an hour.
  • Possible warranty concerns: Any modification to the emission control system can theoretically void warranty coverage for related components. However, a catch can is a reversible bolt-on; returning the truck to stock before dealer visits eliminates this issue.
  • Potential for vacuum leaks: Poor installation—loose clamps, cracked hoses, or incorrect routing—can introduce vacuum leaks. Always double-check the work and use zip ties or heat shield if hoses run near hot surfaces.

Comparison With Other Catch Cans

The aftermarket offers several catch can options for the Tacoma 3.5L. AEM’s unit stands out due to its internal baffle design and proven results. Competitors include the Radium Engineering catch can, the Mishimoto catch can, and generic universal units.

The Radium can is often used in high-performance or racing applications, but its price is higher. Mishimoto offers a direct-fit kit for the Tacoma, though some owners report that it is more difficult to access the drain location. Generic cans are much cheaper but lack the internal engineering to maintain proper crankcase vacuum—they can actually restrict flow and cause pressure buildup, leading to oil leaks or seal damage.

AEM strikes a balance: a reasonable price, vehicle-specific mounting hardware, and a design verified by third-party testing. The 10-horsepower gain documented in dyno tests is not commonly claimed by other manufacturers for a simple catch can install.

For those seeking maximum separation efficiency, there are dual-catch-can setups that intercept both the PCV and fresh-air sides. AEM does not offer a dual kit for the Tacoma, but a single can on the PCV side is sufficient for most street-driven trucks. If the vehicle sees heavy track use or extended idling in cold weather, a secondary can on the fresh-air vent may be beneficial to prevent moisture buildup in the oil.

Owner Testimonials and Community Feedback

The Tacoma community has embraced the AEM catch can as a worthwhile upgrade. On forums such as TacomaWorld and in Facebook groups, dozens of owners have shared their experiences. Here are a few representative voices:

“I installed the AEM catch can at 15,000 miles. I noticed a smoother idle immediately. After 5,000 miles, I emptied about 2 ounces of dark, smelly liquid. The throttle response is definitely sharper, and my butt dyno says it feels stronger. I haven’t dyno’d it, but I believe the numbers.” —Jake R.

“I was skeptical about a catch can adding power, but the dyno sheet doesn’t lie. My truck picked up 10.2 horsepower at the wheels. The can cost me $180 and an hour of labor—that’s the best horsepower-per-dollar I’ve seen on a Tacoma.” —Linda C.

“After a year and 20,000 miles with the AEM catch can, I pulled the intake manifold to clean the valves for a supercharger install. They were virtually spotless. My friend’s Tacoma without a catch can had noticeable buildup at 30,000 miles. That’s the real value.” —Derek M.

These testimonials reflect the common themes: immediate throttle response, measurable power, and long-term cleanliness benefits. While individual results vary based on driving conditions and vehicle maintenance history, the consensus is positive.

Final Verdict: Is the AEM Catch Can Worth It for Your Tacoma 3.5L?

Based on real-world testing and owner feedback, the AEM catch can delivers genuine performance improvements for the Toyota Tacoma 3.5L. The 10-horsepower gain is not a fluke—it is the direct result of reducing oil contamination in the intake system, which improves combustion efficiency and allows the engine to run at its full potential.

For owners who want a simple, reversible, and cost-effective modification that also protects engine internals from carbon buildup, the AEM catch can is one of the best upgrades available. The combination of dyno-verified power gains, improved throttle response, and reduced maintenance makes it a wise investment for both daily drivers and off-road enthusiasts.

Whether you are towing a camper, tackling trails, or just commuting, the AEM catch can helps your Tacoma 3.5L breathe cleaner air and produce more power. As with any modification, proper installation and regular maintenance are key to realizing the full benefits. If you are ready to see what an extra 10 horses feels like behind the wheel, the AEM catch can is a proven path.

For more detailed installation guides and community dyno charts, check out the TacomaWorld forum or the official AEM website. A parts vendor such as Velocity Off-Road also offers AEM catch can kits specifically for the Tacoma, along with installation support.