Complete exhaust system replacement on a 1999 Saab 9-5 (applies to all four cylinder 9-5 models). The original exhaust rusted through, and is now replaced with a three inch straight through system built by Jak Stoll. It is made of 3" aluminized steel piping and includes a downpipe, sport catalitic converter, two flex joints, resonator and a rear muffler.

Jak's fabrication quality got better over the years. The welds and transitions were much smoother than on the NG900 downpipe I bought from him a few years ago. Other than his choice of a resonator, I didn't really have anothing to complain about. The fit was nearly flawless too. He actually mentioned that he doesn't have a jig for 9-5 exhausts at his shop. Instead, he gets his mother in-law's Aero up on the lift and makes a tailored job every time. I suppose this kind of dedication had to pay off ;].

Tools:

  • 22 mm (7/8") crowfoot socket: O2 sensors (or specialized O2 sensor socket);
  • 14 mm socket: reinforcement panel, exhaust clamps and joints (could differ depending on the supplier);
  • 13 mm socket or wrench: downpipe to turbo nuts;
  • flat screwdriver: O2 sensor connectors;
  • torque wrench;
  • ramps and jack stands;
  • anti-seize lubricant;
  • exhaust sealant.
16.09.2008
Just arrived

The system arrived in a huge box filled with packing peanuts. All flanges were carefully wrapped and taped up, so the peanuts wouldn't get inside.
17.09.2008
Unwrapped

The whole exhaust is over four meters (14 feet) long. It was split into four sections for easier shipping, and came with clamps and a chrome tip.
17.09.2008
Downpipe and cat

The downpipe looks smoother than the one I bought from Jak three years ago. It comes with a sport cat and two flex joints before and after cat for better strain resistance (most aftermarket systems have only one flex pipe).
17.09.2008
Middle section

The middle section is a simple straight pipe with an odd noname resonator welded in. As it turned out, it didn't work very well, producing an awful drone between 2-3K RPM. It resonated through the whole car, making the highway ride almost unbearable.
17.09.2008
Resonator

The resonator is just an empty can with baffles designed to reflect and eliminate certain sound frequences. In reality, it only made things worse and had to be replaced with a better one soon after.
17.09.2008
Curved section

The curved section snakes past the fuel tank and under the rear axle. Older cars had an extra pair of hangers at the beginning of this section. Jak skipped it as he used a 2004 Aero for a test fit, but I added them during the install.
17.09.2008
Muffler

The rear muffler is Flo-Pro Max, in an 18" long stainless 4"x9" oval body with a pair of hangers attached.
17.09.2008
Straight through

This picture shows the straight through perforated pipe inside the muffler. It's wrapped in steel mesh and sound absorbing material.
17.09.2008
Clamps and tip

Also included were three Easy Seal clamps and a chrome tip with "Magnaflow" stamped on it.
17.09.2008
Jacks

For exhaust installation, the whole car should be up in the air. I used ramps at the front and jacks in the rear.
17.09.2008
O2 sensor connector

The rear O2 sensor is often hard to undo on the car. Instead, unplug its connector and drop the wires down.
17.09.2008
Heat shield

Remove the heat shield over the turbo. Detach the return pipe from the bypass valve if it's in the way.
17.09.2008
Downpipe

Use a crowfoot or a specialized socket to remove the front O2 sensor. Undo the two upper nuts on the downpipe.
17.09.2008
Lower nut

Mount your creeper, slide under the car and undo the lower nut holding the downpipe. This one needs a 13 mm spanner as there's not enough room for a ratchet.
17.09.2008
Reinforcement

Use a 14 mm socket to unbolt the reinforcement panel under the flex pipe. Slide the panel out.
17.09.2008
Muffler hangers

Remove two rubber supports at the rear muffler. You can see the right side hanger already disappeared some time ago.
17.09.2008
More hangers

All the remaining hangers point forward, so if you give it a good tug towards the back, the whole thing will just drop on the ground.
17.09.2008
Down

Drag the exhaust from under of the car. Watch the top of the downpipe so it doesn't mess up any cables or hoses while being dragged.
17.09.2008
Old exhaust

Such a sorry sight. Big chunks of rust coming off the mufflers, the middle flex pipe's been already replaced at least once, and the front flex is loosing its braiding too.
17.09.2008
O2 sensor

Once the exhaust is on the ground, it should be easy to undo the rear O2 sensor. Again, use a crowfoot or a specialized socket on it.
17.09.2008
New vs old

The new system is shinier, cleaner and noticeably thicker than the original. The original piping is 60 mm (2 3/8"), while new is 76 mm (3").
17.09.2008
Scrap collector

To our surprise, a scrap metal collector showed up while we were working on the car. That solved the problem of disposing of the old exhaust.
17.09.2008
Front section

Start the assembly by connecting the two front sections. Make sure the hangers are aligned evenly.
17.09.2008
O2 sensor and clamp

Install the rear O2 sensor with some anti-seize on the threads and tighten to 40 ft-lbs. Apply a bead of exhaust sealant on the joint and put the clamp on.
17.09.2008
Downpipe hangers

Fit the downpipe in the front rubber hangers.
17.09.2008
Resonator hangers

Hook up the hangers supporting the resonator.
17.09.2008
Downpipe

Slide the downpipe flange onto the turbo, make sure it doesn't rub against the oil pan and the gearbox.
17.09.2008
Rear section

Assemble the two rear sections together. Spread some exhaust sealant, but not tighten the clamp yet.
17.09.2008
Muffler hangers

Fit the muffler and slide the hangers into the rubber supports.
17.09.2008
Rear joint

Jak made all the hangers to point forward, so it was easy to fit the pipe in place.
17.09.2008
Middle joint

Connect the last joint in the middle and move the pipe around to ensure it's perfectly centered along the entire exhaust duct.
17.09.2008
Reinforcement

Secure all the clamps and attach the reinforcement plate at the front. Tighten to 50 ft-lbs.
17.09.2008
Downpipe

Tighten the downpipe nuts to 18 ft-lbs. Use new locking nuts if the old ones feel loose.
17.09.2008
O2 sensor

Install the front O2 sensor, don't forget the anti-seize. Tighten to 40 ft-lbs. Plug in the rear sensor connector.
17.09.2008
Heat shield

Restore the heat shield and the return line from the bypass valve.
17.09.2008
Muffler tip

Attach the muffler tip, make sure it's centered in the bumper cut-out. Start the car and enjoy the new exhaust.
17.10.2008
Small vs large

Unfortunately, as I described above, the resonator was not up to the job, so I got this straight through Magnaflow muffler instead. At 30 inches long and 6 inches wide, it was significantly larger.
17.10.2008
Installed

It had barely enough room to fit under the car, but the result was definitely worth it. The car became virtually as quiet as stock when cruising, with a nice angry note on the throttle.

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