Stainless O2 Housing with External Dump for Mitsubishi Eclipse (1990-1999) 2.0L Turbo

High-Flow Stainless O2 Housing with External Dump for 1990-1999 Mitsubishi Eclipse (1G / 2G DSM)

What it Does: The Stainless O2 Housing with External Dump separates turbine and wastegate discharge on the 1990-1999 Mitsubishi Eclipse to eliminate boost creep and dramatically reduce exhaust backpressure.

The Stock Mitsubishi Eclipse Exhaust Restriction and Boost Creep

The OEM cast-iron O2 housing found on the 4G63T forces wastegate bypass gases to re-enter directly adjacent to the high-velocity turbine exducer stream at a harsh, restrictive angle. This configuration generates severe cross-flow turbulence at the turbine discharge, driving up pre-turbine manifold backpressure and spiking exhaust gas temperatures. When breathing modifications or downpipes are added, the factory housing cannot evacuate sufficient wastegate volume, resulting in uncontrolled boost creep that risks lean detonations. Furthermore, factory cast iron is prone to surface micro-cracking and flange warping under thermal cycling.

The Engineering Solution

This tubular stainless steel O2 housing isolates the internal wastegate circuit through a dedicated 1.5-inch atmospheric dump tube. By routing wastegate flow completely away from the downpipe stream under boost, turbine discharge velocity remains uninhibited, improving spool dynamics and maintaining rock-solid boost control. Engineered with heavy-duty 1/2-inch thick CNC-machined flanges to resist warpage under high exhaust gas temperatures, each joint is precision TIG-welded for maximum structural integrity. The unit includes a pre-welded oxygen sensor bung with plug and clears factory cooling fans, radiators, and standard downpipes.

What's Included

• 1x Stainless Steel Tubular O2 Housing with 1.5-Inch External Dump Tube
• 1x Welded-In O2 Sensor Bung with Threaded Plug

Technical Specifications

Compatibility

• 1990-1994 Mitsubishi Eclipse GS-T / GSX (1G, 2.0L Turbo 4G63T)
• 1995-1999 Mitsubishi Eclipse GS-T / GSX (2G, 2.0L Turbo 4G63T)
• 1990-1999 Eagle Talon TSi / TSi AWD (2.0L Turbo 4G63T)
• 1990-1994 Plymouth Laser RS Turbo (2.0L Turbo 4G63T)
• Compatible with stock turbos (14B, T25) and standard MHI-flanged aftermarket turbos (16G, 20G)

Frequently Asked Questions & Fitment Warnings

Does this fit the 1G and 2G Eclipse?

Yes, this is a direct fit for the 1990-1999 Mitsubishi Eclipse equipped with the 4G63T engine. Does not fit non-turbo models equipped with the Chrysler 420A or naturally aspirated 4G63 engines.

Do I need an ECU tune or boost controller after installing this housing?

Because the external dump eliminates significant post-turbine backpressure and prevents wastegate bottlenecking, an aftermarket boost controller or ECU recalibration is strongly recommended to manage boost levels accurately.

The Mitsubishi Performance Caliber

Engineered for high-boost 4G63T applications, this tubular housing delivers the aggressive external wastegate acoustic signature, optimized exhaust scavenging, and stable boost regulation demanded by serious DSM builders.