3SX NA FED-Spec Downpipe All-New Stainless Steel

3SX All-New Custom Non-Turbo Downpipe (Frontpipe)
Full Stainless Steel


We have re-designed our custom non-turbo downpipes and made them with STAINLESS STEEL this time!

These custom high flow downpipes replace the stock restrictive pipe with a larger diameter and smoother flowing pipe. The pipes from the manifolds are 2" and mandrel bent to merge together into a 2.5" straight through pipe ending in a 2.5" flange.

The 3SX pipe is a 2-piece pipe. The main piece connects to the main cat and rear manifold or rear pre-cat. The Federal-Spec pipe comes with the longer curved front piece that mates up to the front manifold. The California-Spec pipe comes with the shorter straight front piece to connect to the front pre-cat and includes a O2 bung for the O2 sensor.

All 3 gaskets are included.

The 3SX downpipe greatly reduces the restrictions and turbulence created by the stock pipe. This is a great way to add some oompf to the non-turbo cars - both the DOHC and SOHC!!

NOTE: We recommend you check your motor mounts if you still have the original mounts. Worn motor mounts can damage to the flex section in your downpipe, as well as transmission/axle seals, vacuum lines, and other components attached to the engine.


Which NA downpipe do you need?
Federal-Spec versus California-Spec

The distinction of Fed-Spec versus Cali-Spec actually has nothing to do with where you live or where the car came from - they all came from Japan! ;-) It has to do with emissions laws and how they changed over time, and the difference actually is in what year they are...

Federal Spec: As a general rule, all of the 91-93 non-turbos are federal-spec, have only one main catalytic converter between the downpipe and exhaust, have only one O2 sensor mounted just before the main cat and after the flex section, and the downpipe connects directly to both exhaust manifolds.

California Spec: 96+ are Cali-spec. These cars have small "pre-cats" immediately off the exhaust manifolds as well as the main catalytic converter, and have 4 O2 sensors. This pipe connects to the pre-cats, and includes the necessary O2 sensor plug on the front part of the pipe. The 3SX pipe kit includes a O2 plug to plug the hole in the rear of the pipe by the main cat.

94-95 Cars: The 94 and 95 cars are mixed between Fed-Spec and Cali-Spec so you need to check before ordering to determine which model you have.

TIP! Determining your Pipe: We recommend that you check your undercarriage to see which downpipe you need before ordering. An easy way to check is look for the O2 sensor. If it is back in the middle of the car just before the main cat, you need the Fed-Spec pipe, if it is right under the oil pan of the motor and you see the bubble of the front pre-cat, you need the Cali-spec pipe.

Stock Fed-Spec

3SX Fed-Spec
(Old style - use
for illustration

Stock Cali-Spec
(with front pre-cat attached)

3SX Cali-Spec
(Old style - use
for illustration

NOTE: The Fed and Cali spec pipes are NOT interchangeable! You can not get the Fed pipe and use it to try to eliminate the front precat on a Cali car. These pipes are designed specifically to fit either the Fed-spec or Cali-spec vehicles. Use the images and descriptions above to ensure you are ordering the correct pipe. 3SX will not be responsible for shipping or other expenses incurred from ordering the incorrect pipe.

This picture shows what happens if you try install the Fed-spec downpipe on a Cali-spec car.
This being known, you could potentially cut the upper pipe to the rear pre-cat and re-weld the flange at a different angle, and then shorten the front pipe where the two pieces meet. But that is between you and your mechanic. :)


VIDEO! Stock vs 3SX Downpipe. Before and after installing the 3SX NA Downpipe.

Picture of 3SX NA Downpipe SS - Fed-Spec
3SX NA Downpipe SS - Fed-Spec
SKU: 3SXKIT001070
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