2020-2025
2015-2019
2007-2014
2001-2006
Installation Time
(approx) 2 Hours
Difficulty Level:
Simple installation for anyone.
Installation Guides
No guide available for this part yet.
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Magnaflow Direct-Fit Catalytic Converter; OEM Grade (11-14 6.0L Sierra 3500 HD)Find parts that fit my vehicle
Item SHG2818
Sierra 3500 Sales Tech
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M-F 8:30A-11P, Sat-Sun 8:30A-9P
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32 Reviews
Our Price
$1,509.00 each
Ship to: 43215
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Product Information
Features, Description, Reviews, Q&A, Specs & Installation
Features
- Magnaflow Direct-Fit Catalytic Converter
- Made from Stainless Steel
- Crafted with 3.5-Inch Main Piping Diameter
- Seam Welded Design
- OEM Grade
- Built with OE-Like Fitment and Function
- Made to Meet or Exceed Industry-Leading Quality and Safety Standards
- Built with Strict Attention to Details
- Produced in a State-of-the-Art Facility
- With Application- and Vehicle-Specific Properties
- With a Rigorously Tested and Proven Performance
- Boasts a Corrosion- and Rust-Resistant Composition
- Fabricated with a Weather-Tight Structure
- Intended for a Straightforward Installation Procedure
- Requires No Drilling, Modification, and or Cutting
- Backed by a 1-Year Warranty Coverage
- Fits all 2011-2014 6.0L GMC Sierra 3500 HD Models
Description
High-Grade Material Structure. The Magnaflow Direct-Fit Catalytic Converter is the ultimate solution for your 6.0L GMC Sierra 3500 HD's emissions system. Built to OEM grade standards, it guarantees a seamless fit and compatibility with your vehicle's make and model. Crafted from high-quality stainless steel, it not only ensures durability but also resists corrosion, ensuring a longer lifespan. Furthermore, with a generous 3.5-inch main piping diameter, it optimizes exhaust flow, promoting engine efficiency and performance. Its seam-welded design ensures a robust construction, providing reliability and peace of mind.
Easy Installation. What's more? The Magnaflow Direct-Fit Catalytic Converter bolts directly on your 6.0L GMC Sierra 3500 HD without the need to modify your vehicle.
Warranty. This Magnaflow Direct-Fit Catalytic Converter is backed by a 1-year warranty against damages to materials and workmanship.
Application. The Magnaflow Direct-Fit Catalytic Converter is structured to precisely fit all 2011-2014 6.0L GMC Sierra 3500 HD Models.
Fitment:
DetailsMagnaflow 51812
CA Residents: 
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
Installation & What's in the Box
Installation Info
What's in the Box
- (1) Catalytic Converter
4.5
Customer Reviews (32)
Sep 19, 2023
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade (11-16 6.0L Sierra 3500 HD)
2015 SLE - Josesss
Bad
I haven’t been able to to drive the ever since I installed this catalytic converter I don’t know if my was defective my I keep getting p0138 on bank 1 sensor 2
Fit 0/5
Quality 0/5
Bang For Your Buck 0/5
Mar 10, 2025
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade; Passenger Side (15-18 3.5L EcoBoost, 3.5L V6 F-150, Excluding Raptor)
2017 Lariat -
Installation Cost: 500
Installation Time: Shop Install
magnaflow
My OEM Catalytic Converter shipped quickly and on time. Althought I had a shop installed it, there were no issues or concerns with the direct fit of this converter. Price was good as well.
Fit 5/5
Quality 5/5
Bang For Your Buck 5/5
Nov 7, 2024
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade (99-06 4.3L, 4.8L, 5.3L Sierra 1500)
2003 SLE - Do1
Installation Time: Afternoon
Great fitment
Great figment, however you must drop the transmission brace to get the unit up into place.
Fit 5/5
Quality 5/5
Bang For Your Buck 5/5
Aug 6, 2024
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade (16-18 4.3L, 5.3L Silverado 1500)
2016 LTZ - TForesha
Installation Time: Less than 1 Hour
Great part!
Fit and finish good. What you would expect in a quality replacement!
Fit 5/5
Quality 5/5
Bang For Your Buck 4/5
Jun 8, 2024
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade (16-18 4.3L, 5.3L Silverado 1500)
2017 LT - JLSmith
Installation Cost: 100
Installation Time: Shop Install
Happy
Happy that I bought this n got it installed. Worth the money.
Fit 5/5
Quality 5/5
Bang For Your Buck 5/5
May 2, 2024
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade (16-18 4.3L, 5.3L Sierra 1500)
2015 SLT - sierra2015
Installation Time: Less than 1 Hour
Failed
Easy to install, but IT FAILED IN LESS THAN 2 MONTHS. Im having trouble getting it warrantied to get another!!
Fit 5/5
Quality 1/5
Bang For Your Buck 1/5
Mar 29, 2024
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade (16-18 4.3L, 5.3L Silverado 1500)
2016 LTZ - IowaTrucker
Installation Time: Full Day
Excellent Replacement
Both of my upper bank converters failed and the check engine light was on. The dealership wanted $3500 to replace them. I said "thanks, but no thanks." I ordered this part and it arrived within a couple of days. The quality of the part is exceptional. It comes with everything you need for the install, including two new gaskets. You do need to reserve the clamp on your flex tube and use that to connect to this part. The install is somewhat cumbersome for the average weekend warrior. The location of the nuts that attach the converter to the headers are difficult to get to. I ended up rounding off a nut which added several hours to the job. The nuts are 15mm, and finding a 15mm nut extractor proved to be very difficult (and expensive). Be careful here. You also need to remove the transmission support, and support the transmission, but that's not that big of a deal. Removing the O2 sensors/wires was also somewhat difficult. Seemed that some of the plugs were seized in place. I decided to also replace all four of the O2 sensors at this time as well. With 200k miles on the truck and having easy access to replacing them, I figured it was a no brainer. The left side went in with ease. The right side was a little bit of a puzzle to get it in the right place. Once installed, I reset the check engine light and it has stayed off. I've driven about 200 miles so far on the new cats. I also replaced my exhaust with the American Trucks C&L exhaust system. So far, I'm very happy with the end result, even though the exhaust is louder than I'd like. I've noted a marked improvement in my gas mileage as a result of these parts.
Fit 5/5
Quality 5/5
Bang For Your Buck 5/5
Mar 25, 2024
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade (16-18 4.3L, 5.3L Silverado 1500)
2015 LT - Armingo
Installation Time: Afternoon
Got er Done
No more P420 code and and I can accelerate above 50mph again.Side Note you have to remove transmission brace in order to fit on there.Theres a video of installation on YouTube about it.
Fit 5/5
Quality 5/5
Bang For Your Buck 4/5
Feb 24, 2024
Review shared from Magnaflow Direct-Fit Catalytic Converter; HM Grade (99-06 4.3L, 4.8L, 5.3L Silverado 1500)
2006 LT - Greghannah
Installation Time: Afternoon
Perfect fit
Fit perfectly and sounds great paired with Magnaflow exhaust.
Fit 0/5
Quality 0/5
Bang For Your Buck 0/5
Feb 21, 2024
Review shared from Magnaflow Direct-Fit Catalytic Converter; OEM Grade (16-18 4.3L, 5.3L Silverado 1500)
2015 LT - Tyler42015
Product work great on 2015 lt silverado
Worked no more p430 code. Way cheaper then autoparts store and dealer. Did it myself 5 hours need to lower transmission cross bar. Saved thousands.
Fit 5/5
Quality 5/5
Bang For Your Buck 5/5
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