Mitsubishi Sigma Scorpion 1980-1987 2.0L 2.6L Astron Advance Exhaust Headers A342

Advance Headers A342 extractors are designed for selected Mitsubishi Sigma and Scorpion models fitted with the 2.0L 4G52 or 2.6L 4G54 Astron four-cylinder petrol engine.

A342 uses an interference header design suited to standard and mildly modified street engines, with the design intended to improve exhaust gas flow and provide strong usable torque through the normal road-going engine speed range.

Australian Made – heavy-duty press-bent construction.

Bolts and gaskets are included.

Please check availability and current lead time before ordering.

Key Features

• Suits selected Mitsubishi Sigma and Scorpion models
• Suits 2.0L Astron 4G52 engine
• Suits 2.6L Astron 4G54 engine
• Interference design for street performance applications
• Suitable for standard and mildly modified engines
• Heavy-duty construction
• Press-bent header pipes
• Bolts and gaskets included
• Australian Made

Construction

Advance A342 headers feature heavy-duty press-bent construction and an interference design intended for street-driven vehicles.

Press-bent headers use a traditional manufacturing method where the tubing reduces slightly through the bends. This construction has been widely used on Australian performance headers for many years and is particularly well suited to durable street applications.

Additional Options

Please contact Best Mufflers for current availability and advice regarding compatible exhaust components for your Mitsubishi Sigma or Scorpion.

Vehicle Fitment

• Make: Mitsubishi
• Models: Sigma / Scorpion
• Engine: 2.0L / 1995cc Astron 4G52
• Engine: 2.6L / 2555cc Astron 4G54
• Fuel: Petrol
• Drive: Rear-wheel drive

Year Range Note: The original A342 listing stated 1981-1993, however this is not consistent with Australian Sigma and Scorpion production. The Mitsubishi Sigma continued in Australia until 1987, while the Scorpion ended earlier, around 1985. Earlier 1980 models were also available with Astron engines.

Because the exact A342 application boundaries have not been independently confirmed from a current Advance Headers catalogue, please confirm the vehicle model, year and engine before ordering.

Header Specifications

• Part Number: A342
• Brand: Advance Headers
• Design: Interference design
• Construction: Heavy duty
• Pipe Forming: Press bent
• Application: Street performance
• Manufacture: Australian Made

Fitment Notes

A342 is listed for 2.0L and 2.6L Astron-powered Sigma and Scorpion applications. Confirm that your vehicle retains the appropriate longitudinal Astron engine and original-style exhaust layout before ordering.

These vehicles are now several decades old and many have undergone engine conversions, transmission changes or exhaust modifications. Check the engine and existing exhaust configuration before installation.

What's Included

• 1 x Advance Headers A342 header assembly
• Bolts
• Gaskets

Recommended With

Please contact Best Mufflers if you require advice on compatible exhaust components or replacement mounting parts for your Sigma or Scorpion.

Why Good Headers & Exhaust Systems Matter

The 2.0L 4G52 Astron engine theoretically draws approximately 4,000 litres of intake air per minute at 4,000 rpm at 100% volumetric efficiency. Using an illustrative hot exhaust volume at approximately 600°C, this represents around 12,000 litres of exhaust gas per minute.

The larger 2.6L 4G54 Astron theoretically draws approximately 5,200 litres of intake air per minute at 4,000 rpm, representing around 15,600 litres of hot exhaust gas per minute using the same illustrative calculation.

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

Professional installation is recommended. Check exhaust alignment and clearance around the steering, transmission, chassis and surrounding components before completing installation.

Lubricate threaded fasteners with WD-40 or a similar penetrating lubricant before removal to assist with easier removal and installation. After installation and several heat cycles, inspect the system for exhaust leaks and recheck accessible fasteners where appropriate.

Warranty & Compliance

Installation should comply with applicable Australian state or territory requirements relating to exhaust noise and vehicle modifications.

FAQ

Is this product currently available?
Availability and lead times can vary. Please check availability and current lead time before ordering.

What engines does Advance A342 suit?
A342 is listed for Mitsubishi Sigma and Scorpion applications fitted with the 2.0L Astron 4G52 and 2.6L Astron 4G54 four-cylinder petrol engines.

Does A342 suit the Mitsubishi Sigma?
Yes. A342 is listed for selected Sigma models fitted with the 2.0L or 2.6L Astron engine. Please confirm your model, year and engine before ordering.

Does A342 suit the Mitsubishi Scorpion?
Yes. The original Advance application includes the Scorpion with the Astron engine. Please confirm the vehicle details before ordering.

Are these headers mandrel bent?
No. The supplied Advance specification describes A342 as press bent.

Are gaskets and bolts included?
Yes. The supplied A342 product information specifies that bolts and gaskets are included.

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

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