Overview

This guide covers the complete installation of a Greddy SP cat-back exhaust system on a sixth generation Celica. The process provides noticeable performance gains with a deeper, more aggressive exhaust note without being obnoxious.

Required Tools & Equipment

⚠️ Safety First

• Allow exhaust to cool completely before starting work
• Use proper jack stands - never work under a car supported only by a jack
• Wear safety glasses when cutting or hammering
• Work in a well-ventilated area

Step 1: Preparation and O2 Sensor Removal

Once you can safely access the exhaust from underneath (using jack stands), locate the O2 sensor just after the catalytic converter. Remove it using a 22mm wrench - you may need to tap the wrench with a hammer as these sensors are typically very tight. Note: This additional O2 sensor may not exist on all model years.

Step 2: Remove Exhaust Bolts

Attempt to remove the exhaust bolts with a 14mm socket and impact gun. If they won't budge (which is common), you'll need to cut the bolt heads off using an air-powered cutting tool. After cutting, knock out the remaining bolt shafts with an air hammer or drill them out if you don't have air tools.

Step 3: Remove Stock Exhaust

With bolts removed, carefully remove the exhaust system. Start with the cat-to-axle section first. The section that routes over the suspension can be tricky - you may need to cut it with a torch for easier removal. Important: Save the rubber exhaust hangers as you'll need them for the new system.

Step 4: Modify New Exhaust for O2 Sensor (Optional)

If your car has the additional O2 sensor, mark the corresponding location on the new Greddy exhaust. Drill a hole slightly larger than the O2 sensor threading and weld an O2 sensor bung over the hole. Note: This requires welding experience and is challenging due to stainless steel construction. Professional installation recommended.

Step 5: Install New Exhaust System

Install the Greddy exhaust by reversing the removal process. Important: The Greddy exhaust hangers mount in the opposite direction from stock - the metal mounts point the other way. Use lubricant spray on the rubber hangers to ease installation.

Step 6: Final Assembly

Use the provided bolts and gasket to connect the exhaust sections. Install the gasket at the catalytic converter connection (typically only one gasket is provided). For the rear connection, exhaust sealer can be used but isn't strictly necessary due to good alignment. Tighten bolts firmly by hand - avoid over-tightening with impact tools.

🎵 Performance Results

Installation Photo Gallery

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