4"/5" Downpipe-Back Exhaust for 2017-2025 L5P 6.6 Duramax DPF Delete Race Pipe | SPELAB
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Product Information +
- Brand: SPELAB
- SKU: SPES08673S4.0-ES08019SP
- Availability: Many in stock
- Product Type: DPF & Cat Delete Pipe
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PLEASE NOTE!
For 2017-2025 L5P Duramax trucks, this 4/5-inch downpipe-back race pipe reduces factory exhaust restriction and supports tuned setups needing freer flow.
Note: Spelab 6.6L Duramax L5P DP-Back must be used together with our downpipe. The factory downpipe has an integrated SCR assembly and cannot connect directly. Ours must be installed first to allow proper attachment of the subsequent exhaust section.
Unlock your 2017-2025 L5P 6.6L Duramax's true potential with this high-performance DPF delete pipe. Our precision-engineered solution eliminates restrictive factory filters, dramatically reducing exhaust gas temperatures (EGTs) while improving turbo spool-up and throttle response. The mandrel-bent construction ensures maximum flow efficiency, helping your diesel breathe easier. Perfect for off-road enthusiasts seeking better power delivery and reduced maintenance hassles.
L5P Downpipe-Back Exhaust Specifications
| Exhaust Material | T-409 Stainless Steel, it is magnetic. |
| Thickness | 2mm thick for long-lasting durability and heat resistance. |
| Inlet Diameter | 4.0"/5.0‘’ |
| mandrel-bent construction | Maximum flow efficiency, helping your diesel breathe easier |
Benefits of an L5P Downpipe-Back DPF Delete Pipe
Expect to see a significant increase in fuel mileage. If your DPF is plugged up your probably averaging about 13-14 mpg. More or less depending on the severity of the restriction. After deleting the DPF/CAT expect to get a combined mileage of 18-19 mpg.
- It removes the need to service the DPF at regular intervals (cleaning, replacement)
- A DPF delete will remove the possibility of a DPF failure which could cause expensive diesel repairs
- Due to less exhaust backpressure, the DPF delete increases exhaust flow and therefore increases the performance of your motor!
- Paired with an ECU remap, the DPF delete is proven to increase power and torque for all vehicles
Installation Guide and Tuner Requirements
DPF Delete Race Pipe Instruction for L5P
Install takes about 1hr with basic hand tools done on the ground of your driveway or garage. Quicker if you have automotive style lift. Cutting may be be required to fit shorter wheelbase bed/cab configurations. Clamps, hangers and hardware are included. You may have to re-use some factory hardware.
Tuner Required: Removal of the DPF, CAT, SCR, and/or DOC involves removing and eliminating emission related sensors. A DPF delete capable tuner is required to prevent any check engine light or diagnostic trouble codes from setting.
I used this kit all except the elbow so my truck would be axle dumped and I absolutely love it. This kit combined with a TSO exhaust tip gives my truck the rumble and airflow it needs. Definitely satisfied and will order again in the future!
Pretty well put together kit, however upon arrival i knew that there was going to be damages and missing pieces based on condition of box, no way to know if this was fedex or spelabs fault, but regardless, it shouldve been packaged much better considering the cost and size and weight. There was a massive hole in the cardboard that had been taped over and i could see the exhaust before i opened the box. Multiple sections of the exhaust were slightly “egged out” at the connection points, i presume from being dropped, but i fixed them all with giant channel locks. As far as missing parts, only a few nuts and one bolt that had bad threads, so a quick hardware store run was needed. No instructions however it it pretty easy to figure out with trial and error. Getting the hangers mounted is a challenge and requires two people but is easily done with some grit and determination, just dont tighten everything fully until you have all the hangers up, and then just carefully torquing the clamps, i broke a clamp and bolt with my m12 impact, but they included an entire extra clamp, presumably for the extra exhaust section needed for the 8 ft bed. I recommend getting them snug snug with a impact and then using a hand ratchet to tighten the rest of the way, also the free tip doesnt really fit at all. Cheers!
Everything is super high quality, and the absolute best price is could find if i had to complain about anything it would be the exhaust tip I wish the flange for the clamp was .1 longer to get a socket on it.
Exhaust is good but the hangers could use some adjusting. Got a rattle on two trucks that I’m going back after. Not to mention the egr kits not sealing or fitting correctly and missing some components
Installed on a customers truck and turned out wonderful! Kit was very easy to install! We use SPELAB all the time and seldom are unsatisfied.
Love it.
Fast shipping and very good quality parts
Very good quality everything fit perfectly looks and sounds great
Everything fit great except the first exhaust hanger peg wouldn’t reach the original hanger location by the transmission and I had to just leave it off. Also the bolt on the free exhaust tip wasn’t too tight to the tip and couldn’t be tightened enough to clamp it to the pipe. I just bought a smaller bolt and nut and It worked fine. Other than that it worked great.
Great quality. Fit perfect. Not load just right with the muffler.
Good stuff
4"/5" Downpipe-Back 2017-2025 L5P 6.6 Duramax DPF Delete Race Pipe | SPELAB
Works fantastic and the fitment is great!
4"/5" Downpipe-Back 2017-2025 L5P 6.6 Duramax DPF Delete Race Pipe | SPELAB
Awesome fit! Nice install!
4"/5" Downpipe-Back 2017-2025 L5P 6.6 Duramax DPF Delete Race Pipe | SPELAB
Install was a breeze. Nothing missing or damaged. Customer Service was great from time of starting search.
great fitment
Bought one for my 2018 l5p crew cab 8' box fit perfectly went in easy nice sound highly recommend this company
Thanks for the review and look forward to receiving pictures of your install!
Nice quality and looks sharp
Hi, thanks for your comment, looking forward to receiving feedback on your installation pictures!
It was ok. The tail pipe section didn’t not fit as well as it could have. The swedge was terribly oversized. Not sure why 5” exhaust is sold when the first 4’ is 4” pipe. From a flow standpoint point the exhaust is only as good as the smallest restriction. I assume it’s only for sound and not performance. The exhaust hangers could have been placed a little better. There is a spot over the axle that utilizes two hangers in factory form the help keep the exhaust supported and held in place. Spelab uses 1 hanger and the exhaust wants to pull out of the hanger. But these are minor things all in all it was ok. I’d love to have seen a tighter fit for the tail pipe to keep the tip up out of the ground%2C I welded the tubing together to keep the exhaust up tighter to the bed.
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