Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 11 - Jul 16
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
XForce | 3" Varex Valved Cat Back Exhaust | Subaru WRX STI 2003–2007 | E4-SW05VMK5-CBSXForce 3" Varex Valved Cat Back Exhaust System Subaru WRX & STI E4 SW05VMK5 CBS The XForce Cat Back Exhaust System featuring the patented Varex Rear Muffler is the ultimate upgrade for 20032007 Subaru WRX and STI owners who demand total control over their vehicle's acoustic personality. Expertly crafted from high quality raw 409 stainless steel, this system utilize 3" mandrel bent tubing to maximize exhaust flow and significantly improve engine
XForce 3" Varex Valved Cat-Back Exhaust System - Subaru WRX & STI - E4-SW05VMK5-CBS
The XForce Cat-Back Exhaust System featuring the patented Varex Rear Muffler is the ultimate upgrade for 2003–2007 Subaru WRX and STI owners who demand total control over their vehicle's acoustic personality. Expertly crafted from high-quality raw 409 stainless steel, this system utilize 3" mandrel-bent tubing to maximize exhaust flow and significantly improve engine performance. The heart of the system is the Varex valved muffler, allowing you to switch between a discreet, neighbor-friendly quiet mode and an aggressive, high-flow boxer growl at the touch of a button. Whether it's the daily commute or a weekend track day, this system provides the perfect balance of performance, versatility, and style.
What's in the Box?
- 1x 3" Raw 409 Stainless Steel Center Section with Hot-Dog Resonator
- 1x Varex Valved Oval Rear Muffler
- 2x 80mm Polished Exhaust Tips
- 1x Varex Control Kit (Wiring Harness & Remote Keys)
- All Required Gaskets and Hardware
Features:
This product offers the following high-performance features:
- Patented Varex Valve Technology: In-muffler valve control allows for manual adjustment of sound levels from stock-quiet to open-performance.
- 3" Mandrel-Bent Tubing: Ensures a smooth, unrestricted exhaust path for improved turbo spool and horsepower gains.
- Raw 409 Stainless Steel: Durable industrial-grade construction designed to withstand high heat and provide long-lasting service.
- Acoustic Versatility: Equipped with a center hot-dog resonator to refine the tone and a Varex oval rear muffler for ultimate sound customization.
- Twin 80mm Tips: Classic twin-tip design provides a clean, performance-oriented aesthetic that fits perfectly in the factory bumper cutout.
Specifications:
- Make: Subaru
- Model: WRX / STI
- Year Range: 2003–2007
- Material: Raw 409 Stainless Steel
- Pipe Size: 3 Inch (76mm)
- Tip Size: Twin 80mm
- Muffler Type: Varex Valved
Important Information
- The image shown may not reflect the actual product
- Shipping times may vary depending on destination and stock availability
- Fitment Note: Fits Manual transmission vehicles only.
- Installation Note: Some models require connecting pipe E4-SW05-C1 to be ordered separately for bolt-on application when fitting to vehicles with a standalone catalytic converter.
Vehicle Applications:
Vehicle Applications:
| Make | Model | From | To | Body | Series | Engine | Variant | Drivetrain |
|---|---|---|---|---|---|---|---|---|
| SUBARU | ||||||||
| SUBARU | WRX / STI | 2003 | 2005 | Sedan / Wagon | GD / GG | EJ20 Turbo | Manual Only | AWD |
| SUBARU | WRX / STI | 2005 | 2007 | Sedan / Wagon | GD / GG | EJ25 Turbo | Manual Only | AWD |
Warranty Information
| Product Type | Warranty Period |
|---|---|
| 304 & 201 Stainless Steel Exhaust Systems | 60 Months |
| Accessories | 12 Months |
| Catalytic Converters | 12 Months |
| Electronic Products (Including SmartBox) | 12 Months |
| Mild Steel & 409 Stainless Steel Exhaust Systems | 24 Months |
| Mild Steel Headers | 12 Months |
| Stainless Steel Headers | 24 Months |
| Universal 304 Stainless Steel Mufflers | 24 Months |
| Universal Mild Steel & 409 Stainless Steel Mufflers | 12 Months |
Payment & Security:
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.1 ★★★★★
Based on 154 reviews
Sort
Product Reviews
★★★★★ 5
Works if you need help. Not a miracle in a bottle.
Size: 1 Count (Pack of 1)
It has worked every time I've used this product. Won't fix a damage catalytic converter but will help you pass the test if your car almost passed.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 28, 2026
★★★★★ 5
Worked like a charm.
Size: 1 Count (Pack of 1)
Used it as directed. Down to an eighth of a tank. Poured it in and added enough gas to get back to one half a tank. Wanted to get it mixed in really well. Immediately jumped on the interstate and ran 75 MPH for 40 miles. Stopped and filled the tank and when I restarted the engine, the light was off. Coincidence? Not a chance. Light had been on continuously for weeks. AutoZone said I needed a catalytic converter. Nope. One thing I found out the hard way. If your gas filler has a flap at the top, make sure it is easy to push aside. Mine had a little release button near the top that the filler hose would depress before the flap would release. Dumped the first bottle right on the ground. Twelve bucks wasted. No one to blame but me, I guess. Still a bargain, even at twice the price.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 17, 2026
★★★★★ 1
Before use on March 15 two days later March 17 engine light still on
Size: 1 Count (Pack of 1), Size: 1 Count (Pack of 1)
I read the specs on this product and it was guaranteed to cleanse as well as turn engine light off in vehicle. I received it March 14.2026 and used it on March 15.2026 I took a picture on Sunday before I entered it into the gas tank engine light was on at that time. Today is March 17.2026 and engine light is still on. The truck was driven for one hour on the 15th 45 minutes on the 16th and 50 minutes on 17 March. Still the engine light is on. Got home parked the vehicle took a picture again to show engine light is still on product guaranteed it was shut it off, but unfortunately product does not work.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 17, 2026
★★★★★ 4
Good stuff
Size: 1 Count (Pack of 1)
I've used and it's worked for emissions for me and that's with having check engine light on..use stuff,drive around a bit,clear code drive to emissions and should b good unless got serious problems. It's good to use 1 or 2 times a yr if high mileage vehicle.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 1, 2025
★★★★★ 5
It works!
Size: 1 Count (Pack of 1)
My 2005 Jetta failed the inspection and my mechanic said (after clearing the engine light) that I should drive the car for 20 min highway and 20 local. We've tried that the whole day but out of three lights on his device only 1 went away. Next day the light engine came back. After not being happy with the explanation offered by him (a family friend) that I should keep driving it until we get lucky I went online and found CRC 05063. Followed the instruction (one bottle on full tank of gas). Before my tank was under 3/4, engine light went off!! At half tank I went and did the inspection - IT PASSED! I am really impressed!
Update August 2015!
I have been using this product for 2-3 years now and if it is not working for you please read. In July I have used the first bottle and took my 2005 Jetta for inspection. It failed. Ordered a second bottle and it failed again. My mechanic said keep driving. Did 200 miles in one day and nothing. Decided to take matters in my own hands and ordered Autel MaxiScan MS300 ($18, it allows you to read and delete codes). There were two faults - EVAP and 2nd something about Oxygen. Went online and this is the first time I heard about driving cycles. These are steps that you have to follow so that your car's computer can start measuring all the parameters needed for the test. Driving cycles are not exact science but I tried to follow the instructions as much as I could and after just 20 minutes (10min city and 10min highway) ALL the parameters were set and I passed the emission test with flying colors! So, just before you give a comment about CRC like "tried and didn't work" be aware that there are other things you have to take into account.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 1, 2013