Exhaust System Removal and Installation

Overview

This guide walks you through removing and installing the exhaust system on your Porsche 944 S2 with its 16v engine. Whether you’re replacing a worn-out muffler, fixing an exhaust leak, or upgrading components, this procedure ensures everything comes off and goes back on smoothly. It’s a straightforward job for a DIY enthusiast with some mechanical know-how, and it’ll keep your S2 sounding and running great.

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Tools Required

• Metric wrench set (including 13mm wrench)
• Metric socket set
• Pry bar
• Penetrating lubricant (e.g., PB Blaster or WD-40)
• Jack stands
• 5mm Allen wrench

Parts Required

• Exhaust flange nuts and bolts (recommend new hardware, 999 084 052 02 for nuts, 6 per side)
• Exhaust gaskets (if replacing, 944 111 205 03, 2 required)

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Intake Manifold Removal (One-Piece Crossover Pipe Removal Only)

Step-by-Step Procedure

1. Prepare the Vehicle

1. Park your Porsche 944 S2 on a flat surface and let the exhaust system cool completely to avoid burns.
2. Raise the car using a jack and secure it with jack stands under the chassis for safe access to the underside.
3. Spray penetrating lubricant on all exhaust nuts and bolts (especially at the manifold and hangers) to ease removal. Let it sit for 10 minutes.

2. Disconnect the Oxygen Sensor

4. Locate the O2 sensor connector near the firewall at the back of the engine bay.
5. Disconnect the O2 sensor and gently lower the connector down toward the exhaust pipe for clearance.

3. Remove the CO Sample Tube (If Present)

6. Check for the CO sample tube on the exhaust pipe. On many S2s, this has been removed or capped due to rust issues. If yours still has it, it’s connected near the camshaft housing by the engine lifting ring.
7. Unscrew the tube from the exhaust pipe using a 13mm wrench and remove it. Cap the hole if you’re not reinstalling it.

4. Detach the Exhaust Pipe from the Manifolds

8. Find the six nuts and bolts connecting the exhaust pipe to the exhaust manifolds (three per side).
9. Using a 13mm wrench and socket, remove these fasteners. If they’re rusted, apply more penetrating lubricant and work slowly.
10. Support the exhaust system with blocks or jack stands to prevent it from dropping once detached.

5. Remove Exhaust Hangers

11. Locate the hangers: one in front of the catalytic converter, one at the rear of the catalytic converter, and one at the rear of the muffler.
12. Remove the nuts and bolts on each hanger using a 13mm wrench. Keep the rubber mounts intact if they’re still good.
13. With all hangers free, carefully lower the exhaust system from the car and set it aside.

6. Remove the Exhaust Manifolds (Optional)

14. If you’re replacing the manifolds, remove the six nuts and bolts already detached in Step 4 (if not already done).
15. Locate the coolant return pipe attached to the cam housing. Remove the two 5mm Allen head bolts securing it.
16. If the pipe blocks access, you may need to remove it fully. Partially drain the coolant system first (about 2-3 liters) to avoid a mess, then detach the pipe.
17. To remove the manifold studs, loosen each exhaust nut a few turns with a 13mm wrench. Add a second nut, tighten it against the first, and turn the inner nut counterclockwise to back the stud out of the head.
18. Pull the exhaust manifolds off the engine and out of the car.

7. Install the Exhaust System

19. If you removed the manifolds, reinstall them first. Thread the studs back into the head using the double-nut trick from Step 6 in reverse, then attach the manifolds with new gaskets (944 111 205 03) if needed.
20. Lift the exhaust system into place, aligning it with the manifolds. Support it with jack stands or blocks.
21. Secure the exhaust pipe to the manifolds with six new nuts and bolts (999 084 052 02). Tighten to 20 Nm (15 ft-lbs) using a torque wrench.
22. Reattach the hangers at the front of the catalytic converter, rear of the catalytic converter, and muffler with their original bolts or new hardware. Tighten snugly with a 13mm wrench.
23. If the CO sample tube was present and reinstalled, reconnect it to the exhaust pipe and cam housing.
24. Reconnect the O2 sensor and secure the connector near the firewall.
25. If the coolant return pipe was removed, reinstall it with the two 5mm Allen bolts and refill the coolant system as needed.

Post Procedure Checklist

• Lower the car off the jack stands and start the engine.
• Listen for exhaust leaks at the manifold and pipe connections. Tighten bolts if needed.
• Check the O2 sensor connection to ensure it’s secure and the engine runs smoothly.
• If coolant was drained, verify the level in the expansion tank and top off if necessary.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manual, Volume 1
• YouTube