Buy Mercury Cougar Catalytic Converters

The catalytic converter-often nicknamed the cat, cat‑con, or exhaust catalyst-is one of the most important emission‑control parts on every Mercury Cougar made since the mid‑1970s. It sits in the exhaust stream and uses precious‑metal chemistry to clean up harmful gases before they exit the tailpipe, helping the sporty Cougar pass federal and state smog rules while keeping cabin air fresh. When the converter ages or gets damaged, you may see a "Check Engine" light, smell rotten eggs, or fail an emissions test-problems this guide will help you recognize, fix, and avoid. (HowStuffWorks, Kbb.com)

Inside the converter are honeycomb bricks coated with platinum, palladium, and rhodium. In a two‑step reaction, the first "reduction" stage strips oxygen from nitrogen oxides (NOx) while the second "oxidation" stage burns unburned fuel (HC) and carbon monoxide (CO) into harmless nitrogen, carbon dioxide, and water vapor  (HowStuffWorks explains the process).

Every 1990-2002 Cougar uses an OBD‑II-monitored three‑way converter. Earlier 1967‑1989 V8 and V6 models use simpler but bulkier catalysts welded into the Y‑pipe. Always match the converter diameter, flange style, and O2‑sensor bung location to your Cougar's engine code before you buy a direct‑fit or "universal" unit. Using a converter not approved for your exact year in California can lead to a failed smog check-check the CARB aftermarket database for legal part numbers.

• Rotten‑egg odor or sulfur smell from the tailpipe. (JustAnswer, Kbb.com)
• "Check Engine" light with OBD‑II code P0420 Catalyst Efficiency Below Threshold (Bank 1).
• Sluggish acceleration above 30-40 mph because the clogged cat chokes exhaust flow.
• Overheating or glowing converter shell after a long climb-often caused by misfires sending raw fuel into the cat. (HowStuffWorks)

When the upstream and downstream oxygen sensors read almost the same, the Cougar's PCM stores code P0420, telling you that the cat can no longer store oxygen efficiently. Other codes-P0430 (Bank 2), P0171/P0174 (lean), or P0300 (random misfire)-may accompany a failing cat or trigger its premature demise. You can learn more about P0420 symptoms in this Kelley Blue Book guide.

Nationwide averages put a Cougar catalytic‑converter replacement between $1,393 and $1,435, with parts comprising the lion's share of the bill  (RepairPal cost estimator).
Under the federal Clean Air Act, the converter is classed as a "major emission‑control component" and enjoys an 8‑year/80,000‑mile warranty-well beyond the standard 2‑year/24,000‑mile emissions warranty covering most other parts  (EPA warranty FAQ).

Federal law forbids tampering with or removing a working converter, and installing "test pipes" can draw fines. Forty‑plus states mirror that rule, while California and New York require converters to carry a CARB‑issued Executive Order (E.O.) number. Always keep receipts and E.O. paperwork in your glovebox to satisfy inspectors. (California Air Resources Board, US EPA)

Each cat contains about 3-7 g of platinum, 2-7 g of palladium, and 1-2 g of rhodium -precious metals worth recycling when the converter finally plugs up  (Langley Recycling breakdown).
Because these metals fetch high prices, scrap buyers pay well for spent converters, which keeps waste out of landfills but also fuels theft.

Converter thefts surged after 2020. Simple deterrents include:

• Parking inside a locked garage or in well‑lit areas. (NHTSA, Allstate)
• VIN or license‑plate etching on the converter shell.
• Installing a stainless‑steel "cat shield," cage, or strap like the top‑rated plates spotlighted in Car and Driver's lab test.
• Motion‑sensing alarms suggested by Consumer Reports.

Keeping the engine in tune extends cat life: fix misfires quickly, use the correct oil weight to avoid phosphorus contamination, and replace a leaky head‑gasket that lets coolant foul the catalyst. Periodic highway driving keeps exhaust temps high enough to burn off deposits. (HowStuffWorks)

DIY installers should:

1. Disconnect the battery to prevent O2‑sensor damage.
2. Support the exhaust system; remove rusted flange bolts with penetrating oil.
3. Torque new gaskets and spring‑bolts to factory spec and verify no exhaust leaks before road‑testing. Always reuse or install new downstream O2 sensors to avoid false P0420 codes. (manuals.haroldsauto.com, HowStuffWorks)

A bad cat often masks or is triggered by:

• Faulty upstream O2 sensors (commonly replaced with the converter). (RepairPal.com)
• Exhaust manifold cracks that admit oxygen and skew sensor readings. (Kbb.com)
• Secondary air‑injection pumps that fail on early '90s Cougars, causing rich exhaust and catalyst melting. (HowStuffWorks)

Q: What does a catalytic converter actually do?
A: It converts three main pollutants-carbon monoxide, hydrocarbons, and nitrogen oxides-into carbon dioxide, water, and nitrogen using precious‑metal catalysts. (HowStuffWorks)

Q: How long should my Cougar's converter last?
A: Many last 10-15 years, but federal law guarantees at least 8 years or 80,000 miles on the original unit. (US EPA)

Q: Is a universal cat okay?
A: Only if it meets EPA specs; in CARB states you must install a converter with an Executive‑Order number specific to your Cougar. (California Air Resources Board)

Q: Why does my car smell like rotten eggs?
A: Sulfur in unburned fuel reacts inside an overheated or failing converter, releasing hydrogen sulfide that smells like spoiled eggs. (JustAnswer, Kbb.com)

Q: Can I drive with code P0420?
A: Short trips are possible, but ignoring the code can overheat the cat and damage the exhaust or engine-schedule service soon.

Q: How much will repairs cost?
A: Expect roughly $1,400 including parts and labor for a Mercury Cougar, though V8 models and CARB‑legal cats run higher. (RepairPal.com)

Q: Are there eco‑friendly disposal options?
A: Yes-reputable recyclers recover the platinum‑group metals so they can be reused in new catalysts or clean‑energy tech. (Langley Recycling)

Q: How do I keep thieves away?
A: Combine a welded shield, VIN etching, motion alarm, and smart parking habits to make your cat less attractive. (Allstate, Car and Driver)

By understanding how your Mercury Cougar's catalytic converter works, spotting early warning signs, and following these upkeep and security tips, you can keep your classic cat purring cleanly for many miles to come.