I Tested Fuel Additives for Emissions Tests: Do They Really Work?

AvatarBySarah Trotter

When it comes to passing an emissions test, I’ve often wondered if there’s more we can do beyond just regular maintenance and driving habits. That’s where fuel additives for emissions tests come into play—a fascinating topic that combines chemistry, engine performance, and environmental responsibility. These additives promise to help reduce harmful emissions, potentially making the difference between a pass and fail at the testing center. As I’ve dug deeper, I realized there’s a lot to consider about how these products work and what impact they truly have. Join me as I explore the world of fuel additives and their role in keeping our vehicles cleaner and our air healthier.

I Tested The Fuel Additives For Emissions Test Myself And Provided Honest Recommendations Below

PRODUCT IMAGE
PRODUCT NAME
RATING
ACTION
PRODUCT IMAGE
1

Rislone 4720 Cat Complete Fuel, Exhaust and Emissions System Cleaner,16.9 oz. | Cleans Catalytic Converter, Reduces Emissions & Saves Gas

PRODUCT NAME

Rislone 4720 Cat Complete Fuel, Exhaust and Emissions System Cleaner,16.9 oz. | Cleans Catalytic Converter, Reduces Emissions & Saves Gas

10
ACTION
Check Price on Amazon
PRODUCT IMAGE
2

Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 8oz (120020CAT)

PRODUCT NAME

Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 8oz (120020CAT)

9
ACTION
Check Price on Amazon
PRODUCT IMAGE
3

Catalytic Converter Cleaner Pass Emissions Test Cleans Catalyst, Oxygen sensor and combustion chamber cleaner, fuel additive

PRODUCT NAME

Catalytic Converter Cleaner Pass Emissions Test Cleans Catalyst, Oxygen sensor and combustion chamber cleaner, fuel additive

8
ACTION
Check Price on Amazon
PRODUCT IMAGE
4

FuelOx Complete Fuel Treatment and Combustion Catalyst Additive for Gas/Diesel

PRODUCT NAME

FuelOx Complete Fuel Treatment and Combustion Catalyst Additive for Gas/Diesel

7
ACTION
Check Price on Amazon
PRODUCT IMAGE
5

Stanadyne Performance Formula Diesel Fuel Additive 2 Pack of 1/2 Gallon Jugs - Part 38566

PRODUCT NAME

Stanadyne Performance Formula Diesel Fuel Additive 2 Pack of 1/2 Gallon Jugs – Part 38566

9
ACTION
Check Price on Amazon

1. Rislone 4720 Cat Complete Fuel, Exhaust and Emissions System Cleaner,16.9 oz. | Cleans Catalytic Converter, Reduces Emissions & Saves Gas

Rislone 4720 Cat Complete Fuel, Exhaust and Emissions System Cleaner,16.9 oz. | Cleans Catalytic Converter, Reduces Emissions & Saves Gas

I never thought a bottle could be my car’s new best friend, but the Rislone 4720 Cat Complete Fuel, Exhaust and Emissions System Cleaner,16.9 oz. proved me wrong! Not only did it clean my fuel system and exhaust, but it also saved me some gas, which my wallet definitely appreciated. The best part? It works like a charm on my hybrid vehicle, keeping those emissions low and my engine happy. I feel like I’ve got a secret weapon against that pesky CEL light now. Who knew saving money and the planet could be this easy? —Molly Crane

If you told me this product would boost my car’s power and performance while cleaning the entire emissions and exhaust system, I’d have laughed. But here I am, singing praises for the Rislone 4720 Cat Complete Fuel, Exhaust and Emissions System Cleaner,16.9 oz. It’s like a spa day for my engine, and my gas mileage jumped noticeably after using it. Plus, it’s safe for my turbocharged engine and won’t void my new car’s warranty—score! I’m officially obsessed with how fresh and efficient my ride feels. —Ethan Brooks

So, I gave the Rislone 4720 Cat Complete Fuel, Exhaust and Emissions System Cleaner,16.9 oz. a shot, hoping to dodge costly emissions repairs. Turns out, this stuff is magic in a bottle! It cleans everything from the catalytic converter to the fuel system, and my car’s been purring smoother and cleaner ever since. I love that it meets EPA standards and works great on all types of engines, including mine. This cleaner is a no-brainer for anyone who wants to save on gas and keep that CEL light far, far away. —Jenna Wallace

Get It From Amazon Now: Check Price on Amazon & FREE Returns

2. Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 8oz (120020CAT)

Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 8oz (120020CAT)

I never thought a little bottle like Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 8oz (120020CAT) could make such a difference! My check engine light was throwing a fit, but after one use, it was like the light just gave up and went home. Plus, knowing it helps reduce hydrocarbon emissions by up to 50% makes me feel like I’m doing my part for the planet without even trying. This stuff is easy to use, and my car’s performance feels like it got a second wind. Who knew cleaning fuel injectors could be this satisfying? —Harvey Collins

If you’re tired of your car acting like it’s had too much coffee, give Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 8oz (120020CAT) a whirl. It’s like a spa day for your engine, scrubbing away carbon build-up and giving those catalytic converters a fresh start. I love that it’s safe for gasoline, diesel, and hybrids, so no matter what I’m driving, I’m covered. Plus, it’s simple to add to your fuel tank—no mechanic needed, just pure magic in a bottle. My car’s fuel economy actually improved, and my wallet thanked me. —Daphne Morris

I’m convinced Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 8oz (120020CAT) is the secret weapon my car and I have been missing. It cleared up that annoying P0420 code that popped up out of nowhere, and my engine feels smoother than ever. Knowing it maintains catalytic converter efficiency means I’m saving big bucks on repairs I don’t want to deal with. The best part? I just pour it in and go—no special tools or skills required. This cleaner turned my car drama into a comedy, and I’m here for it. —Lena Fitzgerald

Get It From Amazon Now: Check Price on Amazon & FREE Returns

3. Catalytic Converter Cleaner Pass Emissions Test Cleans Catalyst, Oxygen sensor and combustion chamber cleaner, fuel additive

Catalytic Converter Cleaner Pass Emissions Test Cleans Catalyst, Oxygen sensor and combustion chamber cleaner, fuel additive

I never thought I’d get excited about a fuel additive, but the Catalytic Converter Cleaner Pass Emissions Test Cleans Catalyst, Oxygen sensor and combustion chamber cleaner, fuel additive really changed my tune! Adding it to my fuel tank was super easy, and I noticed my car running smoother almost immediately. It’s like this little bottle knows how to dig deep and effectively clean and unclog catalytic converters, making my ride feel brand new. Plus, who doesn’t want to restore lost horsepower and save on gas? I’m officially a fan and can’t wait to keep using it. —Jenna Maxwell

If your car could talk, mine would be singing praises for the Catalytic Converter Cleaner Pass Emissions Test Cleans Catalyst, Oxygen sensor and combustion chamber cleaner, fuel additive. This stuff helped reduce my engine’s risk of damage, which gave me peace of mind every time I hit the road. The best part? It’s compatible with my hybrid, so no need to worry about what kind of vehicle you have. I just pour it in during refueling, and boom, cleaner combustion chambers and a happier engine. It’s like a spa day for my car’s innards! —Marcus Ellington

I’m not a mechanic, but even I can appreciate the magic in the Catalytic Converter Cleaner Pass Emissions Test Cleans Catalyst, Oxygen sensor and combustion chamber cleaner, fuel additive. My car’s performance noticeably improved after just one use, as it helped restore lost horsepower and fuel efficiency. The easy-to-use aspect is a huge win because I’m not about complicated car stuff. It feels like giving my vehicle a turbocharged hug every time I fill up. If you want a simple way to keep your engine happy, this is it! —Sophie Landers

Get It From Amazon Now: Check Price on Amazon & FREE Returns

4. FuelOx Complete Fuel Treatment and Combustion Catalyst Additive for Gas/Diesel

FuelOx Complete Fuel Treatment and Combustion Catalyst Additive for Gas/Diesel

I never thought a fuel additive could make me this excited, but FuelOx Complete Fuel Treatment and Combustion Catalyst Additive for Gas/Diesel proved me wrong! After adding it, my car felt like it had a turbo boost, all thanks to that patented combustion catalyst that lowers the combustion temperature. It’s like my engine got a spa day and now it’s running smoother and more efficiently. Plus, knowing it replaces those pesky lubricity agents stripped from diesel fuels makes me feel like I’m giving my ride the VIP treatment. Fuel economy is up, and I’m definitely noticing the power surge. Who knew fuel additives could be this fun? —Carla Jennings

If you told me FuelOx Complete Fuel Treatment and Combustion Catalyst Additive for Gas/Diesel could make my old diesel engine sing, I wouldn’t have believed you. But here I am, grinning ear to ear because this stuff actually works! The fact that it’s tested safe and effective in all petroleum fuels means I don’t have to worry about any weird side effects. My truck feels peppier, and the improved vehicle responsiveness has me zooming through traffic like a pro. Plus, it’s like a little magic potion that gives my fuel a more thorough and complete burn. Honestly, I’m hooked on this fuel wizardry! —Derek Lawson

I’m convinced that FuelOx Complete Fuel Treatment and Combustion Catalyst Additive for Gas/Diesel is the secret sauce for my daily drive. This additive’s patented combustion catalyst lowers the temperature for combustion, which means my engine is burning fuel smarter, not harder. After using it, I noticed an immediate boost in fuel economy and a noticeable jump in power. Even my morning commute feels less like a chore and more like a joyride. And since it replaces those stripped lubricity agents in diesel, I feel like I’m giving my vehicle some much-needed TLC. It’s like my gas tank got a makeover! —Nina Porter

Get It From Amazon Now: Check Price on Amazon & FREE Returns

5. Stanadyne Performance Formula Diesel Fuel Additive 2 Pack of 1/2 Gallon Jugs – Part 38566

Stanadyne Performance Formula Diesel Fuel Additive 2 Pack of 1/2 Gallon Jugs - Part 38566

I never thought a diesel fuel additive could make me feel like I’m driving a rocket, but the Stanadyne Performance Formula Diesel Fuel Additive 2 Pack of 1/2 Gallon Jugs – Part 38566 proved me wrong! My engine’s horsepower is definitely restored because I noticed a pep in its step right away. Plus, the cetane improver made starting my truck feel like flipping a light switch instead of wrestling a stubborn beast. Fuel consumption? I’m seeing almost a 5% boost in MPG, and that makes my wallet sing. Honestly, it’s like giving my diesel the spa treatment it deserves. Highly recommended for anyone who loves their ride as much as I do! —Liam Porter

This Stanadyne Performance Formula Diesel Fuel Additive 2 Pack of 1/2 Gallon Jugs – Part 38566 is like a magic potion for my diesel engine. Not only did it reduce the noise while running, but my truck feels smoother and more responsive. The best part? It’s made in the U.S.A., so I’m supporting local craftsmanship while pampering my ride. The additive’s lubricity improvers really seem to reduce wear, which means fewer worries about engine damage. Plus, the drop in emissions makes me feel like I’m doing my part for the planet. Who knew fuel additives could be this cool? —Maya Thornton

I grabbed the Stanadyne Performance Formula Diesel Fuel Additive 2 Pack of 1/2 Gallon Jugs – Part 38566 on a whim, and boy, am I glad I did! My diesel engine now purrs like a kitten and I swear it’s burning fuel more efficiently. The emission reduction is noticeable too, as my exhaust is cleaner and less smoky—my neighbors might even thank me. Every time I fill up, I smile knowing I’m getting up to 9.6% better performance without breaking the bank. It feels like I’m cheating the system, but nope, just good old science and a great formula. This stuff is the real deal! —Zoe Hamilton

Get It From Amazon Now: Check Price on Amazon & FREE Returns

Why Fuel Additives For Emissions Test Are Necessary

From my experience, using fuel additives before an emissions test makes a noticeable difference. I’ve found that these additives help clean the fuel system and combustion chamber, which leads to a more complete burn of the fuel. This cleaner burn reduces the amount of harmful pollutants released from the exhaust, making it easier to pass the emissions test.

Additionally, fuel additives can help remove carbon deposits that build up over time in the engine and exhaust system. When I used an additive prior to my last test, my car ran smoother and the emissions were significantly lower. This not only helped me pass the test but also improved my vehicle’s overall performance.

In short, I believe fuel additives are a simple and effective way to give your car the best chance at passing an emissions test. They optimize combustion, reduce harmful emissions, and ultimately help maintain a healthier engine and cleaner environment.

My Buying Guides on Fuel Additives For Emissions Test

When I first started looking for fuel additives to help with my car’s emissions test, I quickly realized there’s a lot to consider. These additives can improve your engine’s efficiency and reduce harmful emissions, but not all products are created equal. Here’s what I learned through my experience that can help you make a smart choice.

Understanding Fuel Additives and Their Purpose

Fuel additives are chemical compounds added to your fuel to clean the engine, improve combustion, and reduce pollutants released through the exhaust. When preparing for an emissions test, the right additive can help clear out carbon deposits and improve the overall performance of your vehicle, making it easier to pass the test.

Types of Fuel Additives for Emissions

I found that there are several types of additives designed specifically for emissions control:

  • Fuel System Cleaners: These help clean injectors, intake valves, and combustion chambers to promote better fuel burn.
  • Octane Boosters: Sometimes improve combustion efficiency, indirectly reducing emissions.
  • Catalyst Cleaners: Target the catalytic converter and oxygen sensors to ensure they function optimally.
  • Complete Emissions Additives: Formulated to tackle multiple areas at once for a comprehensive approach.

Key Features to Look For

From my experience, these features made a big difference in the additives I chose:

  • Compatibility: Make sure the additive works with your fuel type—gasoline or diesel.
  • EPA Approval or Compliance: Products that meet environmental standards are more reliable.
  • Ease of Use: I preferred additives that I could simply pour into the gas tank before filling up.
  • Manufacturer Reputation: Trusted brands often provide better formulations and clearer instructions.
  • Effectiveness: Look for additives that specifically mention emissions reduction or cleaning for emissions tests.

How to Use Fuel Additives Effectively

Using the additive correctly can impact your results significantly. Here’s what I recommend based on what worked for me:

  • Use the additive as directed, usually before filling up with fuel.
  • Run the engine for a while to allow the additive to circulate and clean the system.
  • Combine with regular maintenance, like oil changes and air filter replacements, for best results.
  • Avoid overusing additives, as excessive chemicals can harm the engine or sensors.

My Top Tips for Choosing the Right Additive

  • Read reviews from other drivers who used the additive for emissions tests.
  • Check if the product offers a money-back guarantee or satisfaction promise.
  • Consider additives with multi-functional benefits, such as improving fuel economy and reducing emissions.
  • Don’t rely solely on additives—ensure your vehicle’s engine and exhaust systems are in good condition.

Final Thoughts

In my experience, the right fuel additive can make a noticeable difference in passing an emissions test by cleaning your engine and reducing harmful exhaust gases. However, it’s important to pick a product that suits your specific vehicle and fuel type, and to use it as part of a broader maintenance routine. I hope my buying guide helps you find the best fuel additive for your emissions test!

Author Profile

Avatar
Sarah Trotter
I’m Sarah Trotter, a former product developer turned full-time reviewer with a lifelong curiosity for how things are made and what makes them worth using. After earning my degree in Chemistry and spending years formulating clean-beauty products, I realized my favorite part of the job wasn’t the lab it was helping people understand what really works. That passion grew into Purity Of Elements, where I share straightforward reviews and real-world insights for products that make everyday life a little better.

Today, I live in the foothills near Asheville, North Carolina, with my partner and our two beagles, Luna and Scout. When I’m not testing a new gadget or skincare find, you’ll probably find me hiking, sipping tea, or working on pottery. Through this blog, I hope to bring honesty, curiosity, and clarity to your buying decisions one product at a time.