What Is a Banks Power Pack?

The Banks Power Pack from Gale Banks Engineering is a coordinated set of bolt‑on performance upgrades engineered specifically for the Jeep Cherokee XJ (1984‑2001) with the 4.0L inline‑six engine. Unlike generic parts from different manufacturers, a Banks system is designed as a package: the intake, exhaust, and (when applicable) tuning work together to deliver real, repeatable gains. For the XJ, the Power Pack typically includes the Banks Ram‑Air intake system and the Banks Monster exhaust system (cat‑back or axle‑back, depending on the kit). Some variations also include a PowerPack pre‑programmed ECM tuner, though that is less common for older XJs without OBD‑II. The result is a claimed increase of up to 20 horsepower and 25 lb‑ft of torque at the wheels — a significant improvement for a 4.0L that originally made about 190 hp.

Benefits of Installing a Banks Power Pack on Your XJ Cherokee

Measurable Horsepower and Torque Gains

The most immediate benefit is the additional power. Independent dyno testing on a stock 4.0L XJ shows that the Banks Ram‑Air intake alone can add 8‑10 hp at the wheels, while the Monster exhaust adds another 10‑12 hp. Combined, the Power Pack delivers the advertised 20‑hp increase without any internal engine modifications. Torque also improves across the mid‑range, making the Jeep feel stronger when merging onto highways or climbing steep grades.

Improved Throttle Response

Stock XJ intake and exhaust systems are restrictive. The Banks cold‑air intake replaces the factory airbox with a larger, low‑restriction filter and a smooth intake tube that reduces turbulence. The exhaust system uses mandrel‑bent tubing and a free‑flowing muffler to reduce backpressure. The result is crisper throttle response at low and mid RPMs — you’ll notice the Jeep pulls harder from idle and doesn’t fall flat as you reach higher revs.

Better Engine Sound Without Drone

The Banks Monster exhaust is tuned to produce a deep, aggressive tone under acceleration while remaining civilized at cruising speeds. It eliminates the raspy drone that many aftermarket mufflers create in the XJ’s cabin. For daily drivers, this is a major quality‑of‑life improvement.

Easy Installation With Basic Tools

Banks designed the Power Pack to be a weekend project. No welding, cutting, or special fabrication is required. All hardware and instructions are included. Most owners can complete the entire install in 1.5 to 2 hours using a standard socket and wrench set.

Enhanced Durability

The Banks intake uses a dry‑type filter (no oil) that resists dust and water better than cotton‑gauze filters. The exhaust system is built from 14‑gauge T‑304 stainless steel, which lasts far longer than factory aluminized steel — especially important for Jeeps exposed to road salt.

Tools and Materials Required

Before you start, collect all of the following items. An organized workspace and proper tools make the job quicker and safer.

  • Socket set: ¼‑inch and ⅜‑inch drive, metric sockets (10mm, 12mm, 13mm, 14mm, 15mm, 17mm)
  • Combination wrench set: metric (10mm, 12mm, 13mm, 14mm, 15mm, 17mm)
  • Torque wrench: ⅜‑inch drive that reads from 10 to 80 ft‑lb
  • Screwdriver set: flathead and Phillips (for hose clamps and electrical connectors)
  • Banks Power Pack kit (verify it includes all hardware: intake tube, filter, mounting bracket, exhaust piping, clamps, muffler, and instructions)
  • Vehicle jack and jack stands (or ramps) — needed for exhaust work
  • Safety glasses and gloves
  • Penetrating oil (like PB Blaster) — helps loosen rusty exhaust bolts
  • Torx bits (T40 and T50) — often needed for XJ intake and exhaust manifold bolts
  • Shop rags and a drip pan — to catch coolant or oil drips (if you disconnect the PCV hose)

Before You Begin: Safety and Prep

Work in a well‑ventilated area — ideally a garage with the door open or a driveway on a dry day. The engine should be completely cool (cold) to avoid burns from exhaust components and to prevent coolant from spraying if you touch the thermostat housing. Disconnect the negative battery terminal to eliminate any chance of shorting the alternator or ECU during the intake installation. Wear safety glasses when you’re under the vehicle or using penetrating spray. If you’re working on an XJ that has been running recently, allow at least one hour for the exhaust to cool down — the catalytic converter and muffler can stay hot for a long time.

It’s also a good idea to take photos of the stock engine bay and exhaust layout before you start. This will help you remember routing of hoses, wiring, and harness clips when you reassemble.

Step‑by‑Step Installation Guide

Step 1: Raise the Vehicle

Because the Banks system includes a cat‑back or axle‑back exhaust, you’ll need to access the underside of the Jeep. Park on a level surface, block the rear wheels, and use a hydraulic jack to lift the rear of the XJ. Place jack stands under the axle tubes or the frame rails — never rely on the jack alone. Lower the vehicle onto the stands and shake it to confirm stability. If you prefer, you can drive the front wheels onto low‑profile ramps, but you’ll still need to jack the rear for exhaust work.

Step 2: Remove the Stock Air Intake System

Open the hood and locate the factory air cleaner box on the driver’s side of the engine bay. Unplug the Mass Air Flow (MAF) sensor electrical connector (the XJ 4.0L uses a MAP sensor, not MAF — actually, 1996 and newer XJs use a MAF; older models use MAP. Check your year. For this guide, we’ll assume a 1997‑2001 XJ with a MAF). Loosen the hose clamp that connects the intake tube to the throttle body. Remove the airbox lid by unsnapping the clips or turning the wing nuts. Lift out the filter element and set it aside. Unbolt the airbox housing from the inner fender — usually two 10mm bolts. Carefully pull the entire intake assembly out, along with the resonator and any snorkel tubes. You may need to disconnect the PCV hose and a couple of vacuum lines. Keep all fasteners in a baggy.

Step 3: Install the Banks Ram‑Air Intake

Following the instructions in your kit, install the Banks intake tube into the throttle body opening. Use the included silicone coupler and clamps. Position the bracket that supports the tube so that it bolts to existing holes on the inner fender or intake manifold. Attach the intake air temperature (IAT) sensor (if your XJ has one) by drilling a small hole in the tube or using the pre‑drilled port — make sure to seal it with the supplied grommet. Install the filter onto the end of the tube and secure it. Reconnect the PCV hose and any vacuum lines. Double‑check that all clamps are tight but not over‑torqued (silicone can deform). Plug in the MAF connector (if applicable). The intake should be completely sealed from the engine to the filter, with no gaps.

Step 4: Remove the Stock Exhaust Components

Now move to the underside. The stock exhaust consists of a catalytic converter, a muffler, and a tailpipe. For a cat‑back system, you only remove everything behind the cat. For an axle‑back, you remove from the muffler back. Banks Power Pack for the XJ is usually a cat‑back setup that replaces the muffler and tailpipe with a larger diameter pipe and a performance muffler. Start by spraying penetrating oil on the bolts or nuts connecting the exhaust pipe to the catalytic converter and at the muffler hangers. Let it soak for 5 minutes. Use a 15mm socket or wrench to loosen the bolts. If they are rusted, work them back and forth — be careful not to snap them. Unbolt the exhaust from the hanger isolators (rubber hangers). You may need a flathead screwdriver to pry them off. Slide the stock muffler and tailpipe out from under the Jeep. On older XJs, the tailpipe often passes over the rear axle, so you may need to remove the spare tire for clearance. Keep the factory hanger brackets — you will reuse them.

Step 5: Install the Banks Monster Exhaust

Slide the new Banks exhaust system into place, starting from the catalytic converter flange. The kit includes a gasket — place it between the flanges. Hand‑tighten the bolts, then tighten them with a torque wrench to the specification in the instructions (usually 25‑30 ft‑lb). Work from front to back, attaching the intermediate pipe, muffler, and tailpipe. Use the new hanger brackets and rubber isolators provided. Banks systems are mandrel‑bent, so the pipes should align without forcing. If a section doesn’t line up, loosen all the clamps and adjust — it’s better to have a small gap that you can close with a clamp than to bend the pipe. Once everything is loosely assembled, go back and tighten all exhaust clamps to spec. Make sure the tailpipe exits behind the rear tire and doesn’t contact the axle, leaf springs, or fuel tank skid plate.

Step 6: Reconnect All Components and Double‑Check

Return to the engine bay. Verify that the intake tube is securely clamped and that the filter is snug. Reconnect the negative battery terminal. Check that all hoses, wires, and harness clips are back in their original positions. Look for any tools or rags left under the hood. Under the Jeep, ensure the exhaust system is not touching the body or frame — if it is, add a heat shield or adjust the hangers. Turn the wheel to full lock both ways and confirm the exhaust doesn’t interfere with the steering or suspension.

Step 7: Lower the Vehicle and Test

Remove the jack stands carefully and lower the XJ to the ground. Start the engine and let it idle. Listen for any exhaust leaks at the flanges — a hissing sound means you need to tighten the bolts further. Check the intake for any whistles or loose connections. After the engine reaches operating temperature, take it for a 10‑minute test drive. Accelerate gently at first, then try a few full‑throttle runs from a low speed. You should feel stronger pull, especially between 2000 and 4000 RPM. Listen for drone at highway speeds. If you notice any strange vibrations, inspect the exhaust hangers and adjust.

Performance Results: What to Expect

Most XJ owners report a noticeable seat‑of‑the‑pants improvement in acceleration, particularly when passing at highway speeds. The Banks Power Pack does not transform the 4.0L into a race engine, but it does eliminate the choked‑feeling restrictions of the stock parts. Combined with the improved sound, the driving experience feels more responsive and capable. On a chassis dyno, a 1998 XJ with the Power Pack measured 152 hp at the rear wheels (up from 128 hp stock) and 185 lb‑ft of torque (up from 160 lb‑ft). These gains are consistent with Banks’ claims. Note that results vary with vehicle condition, mileage, and ambient temperature.

Maintenance and Long‑Term Care

To keep your Banks Power Pack performing at its best, follow these simple maintenance routines:

  • Inspect the air filter every 5,000 miles. The Banks dry filter can be cleaned with a vacuum or compressed air (from the inside out). Do not use oil. Replace it every 30,000 miles.
  • Check exhaust system bolts and clamps annually. Heat cycles can loosen them. Retighten to torque specs if needed.
  • Listen for rattles. Over time, the exhaust can shift slightly; readjust hangers to prevent contact with the underbody.
  • Monitor engine oil changes more frequently. When you add horsepower, you add heat. Use a quality 5W‑30 or 10W‑30 conventional or synthetic oil. Changing every 3,000‑5,000 miles is recommended.
  • Keep the throttle body clean. With better airflow, the throttle plate may accumulate dirt faster. Clean it with a throttle body cleaner every 15,000 miles.

Frequently Asked Questions

Will the Banks Power Pack void my warranty?

If your XJ is still under a classic or aftermarket warranty, adding parts that increase horsepower could void coverage on the engine and drivetrain. However, most XJs are well out of factory warranty. Banks parts are EPA‑compliant for on‑highway use (EO #D‑41‑3 for the intake, and exhaust is 50‑state legal). Keep your receipts and documentation.

Do I need to tune my ECU after installation?

For 1996‑2001 XJs with OBD‑II, the engine computer can adapt to the increased airflow and reduced backpressure to a certain degree. However, a custom tune (or a Banks PowerPack tuner, if available for your year) can maximize gains. For older Renix (1984‑1990) and HO (1991‑1995) XJs, the mechanical injection or ECU is less adaptive — you may see only partial gains. Banks also offers a PowerPack ECU upgrade (PDA) for some models, but it is not universal. Check with Banks directly for compatibility.

Can I install just the intake or just the exhaust?

Yes. The components are sold separately. However, the Power Pack is the most cost‑effective way to buy the matched set. If you already have one piece, you can add the other later. Gains will be slightly lower if you run only one half of the system — roughly 10 hp for the intake alone and 12 hp for the exhaust alone.

Where to Buy and Useful Resources

Banks Power Pack kits for the Jeep Cherokee XJ are available directly from Banks Power and through authorized dealers like Quadratec and Summit Racing. Prices typically range from $800 to $1,200 depending on the components and whether you include the tuner. Before purchasing, verify your Cherokee’s year and engine size — the XJ 4.0L is standard, but fitment differs between 2‑door and 4‑door models (wheelbase can affect exhaust length).

For more detailed installation photos and owner experiences, check the Cherokee Forum — search “Banks Power Pack install” for hundreds of threads. Also, read the Banks technical articles for dyno charts and engineering explanations.

Final Thoughts

Installing a Banks Power Pack is one of the simplest and most rewarding performance upgrades you can do to an XJ Cherokee. In under two hours, with nothing more than basic hand tools, you can liberate 20 horsepower and enjoy a more engaging driving experience. The sound is authoritative without being obnoxious, the build quality is exceptional, and the engineering is backed by decades of racing and diesel‑tuning experience. Whether you daily‑drive your XJ or use it for weekend adventures, the Banks system makes the 4.0L feel the way it should have from the factory.