Sport Air Intake System for Cadillac Seville SLS / STS (1998-2004) with 4.6L V8 Engine Blue

Restore the Breath of Your 4.6L Northstar V8 Cadillac Seville SLS & STS

Who It’s For: Designed specifically for 1998–2004 Cadillac Seville owners running the legendary 4.6L Northstar V8 engine.

The Problem: The Northstar V8 is a high-revving, 32-valve masterpiece, but the factory air box was engineered for silence over performance. The stock plastic housing and restrictive paper filters create a significant bottleneck, preventing the engine from reaching its true volumetric efficiency. Over time, these factory plastic components can become brittle and heat-soaked, further robbing your Cadillac of its luxury-performance edge.

The Solution: We engineered this Sport Air Intake to eliminate the factory restrictions of the Northstar V8. By replacing the baffled stock air box with a high-velocity aluminum tube and a high-flow washable filter, we allow the engine to pull in a higher volume of oxygen with less resistance, correcting the factory’s conservative airflow tuning.

Why This is the Ultimate Upgrade

• Optimized Air Velocity: Delivers up to a 10% increase in horsepower and torque by reducing intake turbulence and increasing the volume of air reaching the manifold.
• Professional Grade Materials: Constructed from mandrel-bent lightweight aluminum piping which dissipates heat faster than stock plastic and provides a lifetime of durability.
• Deeper V8 Note: Removes the factory resonators to provide a deep, sporty engine growl under acceleration while maintaining cabin refinement during cruising.
• Long-Term Value: Features a high-performance washable filter, eliminating the need for expensive paper filter replacements.

Technical Specifications

Compatibility & OEM Reference

Fits the Following Vehicles:

• 1998 Cadillac Seville SLS / STS 4.6L V8
• 1999 Cadillac Seville SLS / STS 4.6L V8
• 2000 Cadillac Seville SLS / STS 4.6L V8
• 2001 Cadillac Seville SLS / STS 4.6L V8
• 2002 Cadillac Seville SLS / STS 4.6L V8
• 2003 Cadillac Seville SLS / STS 4.6L V8
• 2004 Cadillac Seville SLS / STS 4.6L V8

Interchange Part Numbers:

SI-C-12B, 1998, 1999, 2000, 2001, 2002, 2003, 2004, Cadillac, Seville, SLS, STS, 4.6, 4.6L, V8, Northstar

The Performance Promise

Buy with confidence. This system is designed for a direct bolt-on installation using basic hand tools in under 60 minutes. It is a legal and effective way to improve throttle response. Consult your dealer about warranty coverage for aftermarket parts. After installation, we recommend disconnecting your battery for 10 minutes to allow the PCM to recalibrate for the increased airflow.

Common Questions

Will this intake fit both the Cadillac Seville SLS and STS trims?
Yes, this system fits all 1998–2004 Cadillac Seville SLS and STS models equipped with the 4.6L Northstar V8 engine.

Does this work on both the 275 HP and 300 HP 4.6L V8 engines?
Yes, this intake fits both the 275 HP LD8 engine in the SLS and the 300 HP L37 engine in the STS for 1998–2004 Cadillac Seville models.

What is included with the intake system?
The kit includes mandrel-bent lightweight aluminum intake piping and a high-flow washable air filter to replace the restrictive factory plastic air box.

How long does installation take and what tools are needed?
It is a direct bolt-on installation that takes under 60 minutes using basic hand tools. Disconnecting the battery for 10 minutes afterward is recommended so the PCM can recalibrate for the increased airflow.

What kind of performance gains can I expect?
By reducing intake turbulence and removing the factory air box restrictions, this system delivers up to a 10% increase in horsepower and torque along with a deeper V8 engine note under acceleration.