Go-Parts
Cart 0
Your cart is empty
Add an item to see it appear here.
Wrenchy
Go-Parts Garage
Expert guides for diagnosing, troubleshooting, and replacing auto parts Expert guides for diagnosing and replacing auto parts
Browse All →
🛍️ Shop This Part

Subaru XT Catalytic Converter: A Guide for 1985-1991 Models

Everything you need to know about choosing the right new aftermarket catalytic converter for your classic Subaru XT.

3 minutes to read 1985-1991 Subaru XT
Difficulty
3/5
Est. Time
2.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$200-$350
Used OEM Price
$50 - $200 (Varies greatly by condition and source)
⚠️ Drivable, but... — You can drive, but a clogged converter can cause severe power loss and potentially lead to engine damage from excessive backpressure over time.
Key Takeaways
  • OEM parts are likely unavailable; aftermarket direct-fit converters are the standard replacement.
  • Symptoms include power loss, rattling from the exhaust, and a rotten egg smell.
  • Brands like MagnaFlow offer premium quality at a higher price, while Walker, AP Exhaust, and Eastern Catalytic provide more budget-friendly options.
  • No specific recalls or TSBs exist for the catalytic converter on the 1985-1991 Subaru XT.
The catalytic converter on your 1985-1991 Subaru XT is a critical part of your exhaust system. It's located between the engine's exhaust manifold and the muffler. Inside the converter, a honeycomb structure coated with precious metals like platinum and palladium gets superheated by the exhaust. This heat triggers a chemical reaction that converts harmful pollutants from your engine—like carbon monoxide and nitrogen oxides—into less harmful gases such as carbon dioxide and water before they exit the tailpipe. A properly functioning converter is essential for passing emissions tests and ensuring your engine runs smoothly.

Is Your Subaru XT Catalytic Converter Failing?

Catalytic converters don't last forever. Over decades of use, the internal ceramic honeycomb can break down from heat and vibration, or it can become clogged with carbon deposits. Contamination from engine oil or coolant leaks can also ruin a converter by coating the catalyst materials. Because the Subaru XT is a classic vehicle, it's common for the original converter to be at the end of its life.

Choosing the Right Aftermarket Converter

For a vehicle from the 1985-1991 era, finding a brand-new Original Equipment Manufacturer (OEM) catalytic converter from Subaru is highly unlikely and would be extremely expensive if found. The most practical and common solution is to use a new aftermarket part. Aftermarket brands offer a range of options that fit different budgets and needs. They are generally categorized as direct-fit or universal. A direct-fit part is designed to bolt right into the original location with no modifications, while a universal part may require cutting and welding for a proper fit. For a straightforward installation on your XT, a direct-fit model is recommended.

Aftermarket Brand Tiers for Your XT

Tier Brands Quality & Cost Assessment
Premium MagnaFlow, MagnaFlow Performance Exhaust Known for high-quality stainless steel construction, durability, and sometimes improved exhaust flow. They are a top-tier aftermarket choice but come at a higher price point. Often considered one of the most trusted aftermarket brands by mechanics.
Standard / Mid-Grade Walker Exhaust A well-known and trusted name in exhaust parts, offering a good balance of quality and affordability. Walker provides reliable direct-fit options that are a popular choice for daily drivers and restorations. Some users report lower longevity compared to premium brands.
Economy / Budget AP Exhaust, Eastern Catalytic These brands are widely available and offer the most budget-friendly options. They are a practical choice if keeping costs low is the primary goal. However, some forum users have reported mixed results regarding exact fitment and long-term durability compared to more expensive brands.

Known Issues, Recalls, and Service Bulletins

Based on extensive research, there are no specific recalls or Technical Service Bulletins (TSBs) from Subaru or the NHTSA related to the catalytic converter for the 1985-1991 Subaru XT. This is not unusual for a vehicle of this age. Any failures are typically due to normal wear and tear over several decades of use.

Frequently Asked Questions (FAQ)

Can I use a universal catalytic converter on my Subaru XT?

Yes, but it's not recommended unless you are experienced with exhaust work. Universal converters require cutting your existing exhaust pipes and welding the new part in place. A direct-fit converter is designed to bolt on, making the job much simpler and faster.

Will a new converter fix a P0420 error code?

A P0420 code ("Catalyst System Efficiency Below Threshold") often points to a failed catalytic converter. However, a bad oxygen sensor or an exhaust leak can also cause this code. It's wise to have a mechanic diagnose the issue properly before replacing the converter to avoid spending money on a part you may not need.

Why do some aftermarket converters cost so much more than others?

The cost difference is usually due to the materials used and the amount of precious metals in the catalyst. Premium brands like MagnaFlow often use more durable stainless steel and a higher loading of catalyst materials, which makes them more effective and longer-lasting. Budget brands may use less expensive materials to keep the price down.

Do I need a CARB-compliant converter for my XT?

If your vehicle is registered in California or a state that has adopted California's strict emissions standards, you legally must install a CARB-compliant catalytic converter. These are more expensive because they meet stricter performance and durability requirements. Always check your local state regulations before purchasing.

Technical Specifications

Varies by brand. Available in direct-fit and universal configurations. Check for federal (EPA) or California (CARB) emissions compliance based on your state's requirements.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Jul 21, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Catalytic Converter for:
  • Subaru XT: 1985198619871988198919901991
In this article
🛍️ Shop This Part
Jump to ▴

Email This Guide

We'll send you a link to this article so you can read it later or share it.

Added to cart · Part