Jeep Cherokee XJ Grand Cherokee ZJ 4.0L Headers – Wildcat WILD091

Wildcat WILD091 exhaust headers (extractors) are designed for selected Jeep Cherokee XJ models from 1994–2001 and Jeep Grand Cherokee ZJ models from 1994–1998 fitted with the 4.0L inline 6-cylinder petrol engine, commonly known as the AMC 242 / Jeep 4.0L engine.

Featuring an interference-style header design, WILD091 replaces the restrictive factory exhaust manifold with larger performance pipework designed to improve exhaust gas flow and scavenging. The combination of 1.50" primary pipes, 2.00" secondary pipes and a 2.50" outlet is designed to improve torque, throttle response and usable engine performance.

WILD091 is designed as a direct bolt-on replacement for the applicable factory exhaust manifold and is suitable for street, touring and off-road applications.

MADE TO ORDER – WILD091 headers are currently made to order and may take approximately 4–6 weeks. Please check availability and current lead time before ordering.

Key Features

• Designed for selected Jeep Cherokee XJ 1994–2001 models
• Designed for selected Jeep Grand Cherokee ZJ 1994–1998 models
• Suits the 4.0L inline 6-cylinder petrol engine
• Interference-style design for street, touring and off-road applications
• 1.50" (approximately 38mm) primary pipes
• 2.00" (approximately 51mm) secondary pipes
• 2.50" (approximately 63mm) outlet
• Direct bolt-on application
• Designed to improve exhaust flow, torque, throttle response and engine performance

Construction

• Australian-made Wildcat performance headers
• Quality mild steel construction
• Strong welded construction for durability
• Heat-resistant painted finish rated to approximately 600°C
• Heavy-duty cylinder-head mounting flange

Additional Options

• DSF804G: Exhaust manifold/header gasket available separately
• Replacement manifold bolts and exhaust hardware where required

Vehicle Fitment

• Make: Jeep
• Model: Cherokee
• Series: XJ
• Year Range: 1994–2001
• Engine: 4.0L inline 6-cylinder petrol

• Make: Jeep
• Model: Grand Cherokee
• Series: ZJ
• Year Range: 1994–1998
• Engine: 4.0L inline 6-cylinder petrol

Fitment Notes

• Suits selected Jeep Cherokee XJ 1994–2001 4.0L applications
• Suits selected Jeep Grand Cherokee ZJ 1994–1998 4.0L applications
• Direct bolt-on replacement for the applicable factory exhaust manifold
• Vehicle modifications, engine conversions, engine mounts, steering components or non-standard exhaust systems may affect clearance and fitment
• WILD091 is currently made to order and may take approximately 4–6 weeks
• Please check availability and current lead time before ordering.

What’s Included

• 1 x Set Wildcat WILD091 headers / extractors
• HTG549 base gasket with bolts

Recommended With

• DSF804G exhaust manifold/header gasket for cylinder-head fitment
• Replacement manifold bolts and nuts where existing hardware is worn or corroded
• Quality performance exhaust system where further exhaust flow improvement is required

Why Good Headers & Exhaust Systems Matter

At 4,000 rpm, the 4.0L Jeep inline 6-cylinder engine draws in approximately 8,000 litres of intake air per minute and expels around 24,000 litres of hot exhaust gas per minute at approximately 600°C. A well-designed header and exhaust system helps manage this high gas flow efficiently, reducing restriction and improving exhaust scavenging, torque, throttle response and engine performance.

Installation Tips

Apply penetrating lubricant such as WD-40 or similar to the manifold bolts, nuts and exhaust fasteners before removal. Remove all traces of the old gasket material and inspect the cylinder-head sealing surface before installation. Trial-fit the headers and check engine, steering, transmission and body clearance before final tightening. Inspect all exhaust connections and mounting hardware and replace worn or corroded components where required.

Warranty & Compliance

Wildcat headers are covered by the applicable 2-year manufacturer's warranty against manufacturing defects, subject to standard warranty terms and conditions. Incorrect installation, modification or damage caused during installation is not covered.

Installation must retain the catalytic converter, oxygen sensors and any other emissions-control equipment required for the vehicle. Exhaust and emissions requirements vary between Australian states and territories, and the completed installation must comply with the regulations applicable in your state or territory.

FAQ

What vehicles do WILD091 headers suit?
WILD091 is designed for selected Jeep Cherokee XJ models from 1994–2001 and Jeep Grand Cherokee ZJ models from 1994–1998 fitted with the 4.0L inline 6-cylinder petrol engine.

Are WILD091 headers direct fit?
Yes. WILD091 is designed as a direct bolt-on replacement for the factory exhaust manifold on the applicable standard vehicle configuration.

What size are the WILD091 header pipes?
WILD091 uses 1.50" primary pipes, 2.00" secondary pipes and a 2.50" outlet.

What is supplied with WILD091?
WILD091 is supplied as a header/extractor set with an HTG549 base gasket and bolts.

Which cylinder-head gasket is recommended?
The recommended exhaust manifold/header gasket is DSF804G, available separately.

Are WILD091 headers made to order?
Yes. WILD091 headers are currently made to order and may take approximately 4–6 weeks. Please contact us for current availability and lead time before ordering.

What finish is used on WILD091?
The headers have a heat-resistant painted finish rated to approximately 600°C.

Are WILD091 headers Australian made?
Yes. Wildcat WILD091 headers are manufactured in Australia.

Can I pick up from the store?
Yes. Pick up is available but must be pre-arranged before collection.

How much is freight?
Freight varies depending on your delivery location and where stock is available. Please contact us for freight charges before ordering. Where possible, we can arrange dispatch from the nearest available product location to help reduce freight costs and delivery times.

Do you ship to the USA?
Yes. Best Mufflers regularly ships exhaust systems and exhaust parts to customers throughout the United States.

Please note that import duties, tariffs, taxes, and customs clearance fees are not included in the product or shipping price. Once your order is processed and the applicable charges are calculated, we will send you a secure payment link to finalise the import duties and tariff charges before dispatch.

Customer Support

For phone orders, fitment advice or product enquiries, contact Best Mufflers:

Call Now: +61 2 9547 3511 Email Us

Best Mufflers
87A Planthurst Road, Carlton NSW 2218, Australia
Monday–Friday 8:00am–5:00pm by appointment
Exhaust Systems Since 1983