Quick Answer: F-150 3.0L 4-Inch DPF Turbo-Back Pipe Installation
Fit a 2018–2019 F-150 3.0L 4-inch turbo-back system from both ends toward the center. Leave the downpipe and intermediate section loose. Hang the rear pipe, muffler or matching straight section, and tailpipe in their mounts. Measure the center extension only after those positions are set, then align and tighten from the turbo toward the tailpipe.
Before you start: Confirm the 4-inch option and year before booking lift time. The illustrated sequence shows the supported measuring points and rear route; it also needs to be checked against the parts actually supplied: F-150 3.0L 4-Inch Exhaust Installation PDF.
Confirm The F-150 Exhaust Option Before Booking Lift Time
Before booking lift time, confirm the exact 4-inch option you have. The straight and muffler versions need the right instructions, and the 3.5-inch kit keeps a different rear layout.
For this route, the rear measuring point must be in its frame supports before the extension is cut. A helper and a clear plan for the retained mounts make that check easier.
U.S. emissions rules prohibit tampering with certified controls. A race-use label alone does not establish an exemption.
Choose The F-150 4-Inch Version First
| Vehicle or layout check | What applies here |
|---|---|
| Truck covered | 2018–2019 Ford F-150 3.0L Powerstroke. |
| Replacement route | Full 4-inch turbo-back route, including the replacement rear exhaust. |
| Center option | Use the actual muffler or matching straight center section for the assembly being installed. |
| Length references | Intermediate hanger and rear frame supports must be seated before measuring the extension. |
| Access | The illustrated procedure calls for a lift or hoist and at least two people. |
Before You Remove Anything: This guide covers the 2018–2019 3.0L Powerstroke F-150 with a full 4-inch turbo-back route. Confirm the turbo flange, box length and center-section option. A muffler version and a straight-pipe version must each use a center section with matching ends and length.
The 4-Inch Front, Extension And Rear Parts
| Component name | Illustrated manual reference | How to identify or fit it |
|---|---|---|
| Downpipe/front pipe | 31831 | Starts at the turbo connection. |
| Intermediate pipe | 31842 | Hanger seats in the original rubber isolator. |
| Center extension | 40020 | Trim only after the supported rear section is located. |
| Rear supported pipe | 31515 | Uses the applicable frame hangers. |
| Muffler/center-section reference | 6185 | Verify the actual muffler or straight-section option supplied. |
| Over-axle tailpipe | 31517 | Fit its supports while connecting the center section. |
Use the shapes, pipe ends and welded supports in this drawing to match the components listed above.
Lift, Helper And Supported Work Areas
| Tool Or Equipment | What You Need It For |
|---|---|
| Vehicle and exhaust support | Lift or hoist, at least two people and exhaust stands. |
| Front connection | 15 mm socket for the two nuts, as listed by ES09033. |
| Skid plate | 8 mm and 11 mm tools for the matching F-150 access hardware; confirm the actual heads on the truck. |
| Measuring and fastening | Tape measure, marker, cutting tools if needed and a torque wrench with the supplied hardware specifications. |
Start with a cold exhaust. Support the truck by the approved method and support each heavy pipe before release. Never work under a jack alone.
Phase 1: Release The Original Route And Preserve The Rear Mount
Installer Tip: Keep the spare-tire heat shield in place while checking the tailpipe route. Recheck pipe rotation and support positions rather than removing protection to hide a fit problem.
Step 1: Check The Front And Rear Parts
Lay out the downpipe, intermediate pipe, center extension, rear supported pipe and tailpipe by their ends and hangers. Identify whether the actual center option is a muffler or matching straight section before measuring. A different center-section length changes the installed rear gap.
Step 2: Set Up The Lift And Helper
Use a lift or hoist and at least two people for the illustrated removal. Support the heavy sections before release. Remove the skid plate, keeping the hardware together. The matching F-150 access arrangement uses four 8 mm bolts and one 11 mm nut. Label the exhaust connections and keep leads out of the removal path.
Step 3: Save The Rear Hanger
Release the muffler/mid-pipe clamp and the pictured hangers. Keep the frame hanger used by the new rear pipe. Support the stock sections as you separate the center flange and locator joint.
Original frame-hanger locations used during removal. ES09033.
Original locator feature at the flange connection. ES09033.
Step 4: Remove The Stock Downpipe
The guide lists a 15 mm socket for the two nuts at the turbo connection. Keep the pipe supported while you release it. Save the hardware the kit reuses and check the mating surfaces.
Phase 2: Set The Downpipe And Intermediate Joint
Step 5: Fit The Downpipe And Intermediate Joint Loosely
Fit the downpipe at the turbo connection and leave it adjustable. Join the intermediate pipe while seating its hanger in the stock rubber mount. The illustrated front/intermediate slip joint uses 1.25 inches of overlap, with the clamp at the expanded-end edge. The stray front-pipe label in the PDF does not add another section to this route.
Phase 3: Build The Supported Rear Route
Step 6: Hang The Rear Pipe Before Cutting
Hang the rear supported pipe in its frame mounts, refitting the saved support where required. The illustrated arrangement may use one or both frame supports. With this pipe and the intermediate section seated, measure the gap for the center extension. Add the actual insertion at each receiving end once, then mark a suitable plain-end trim.
Before the Cut: Check What the Gap Measurement Includes
For one extension with two slip joints, finished length equals the end-face gap plus the front insertion plus the rear insertion. Do not add overlap again if your measurement already includes it. A flange or butt joint does not use that slip-joint calculation.
Trial-fit the marked length, cut only the permitted plain end and remove burrs. Refit the extension and check the witness marks before tightening.
Step 7: Fit The Actual Muffler Or Straight Center Section
Fit the actual muffler or its matching straight center section behind the rear supported pipe and hold it on a stand. Follow any direction marking on the part. Keep this joint adjustable while fitting the tailpipe; do not substitute a different-length center option after the extension has been cut.
Step 8: Route The Tailpipe Over The Axle
Feed the tailpipe over the axle from the rear. With a helper, engage the pipe joint and both supports together. If the spare-tire shield is close, first turn the loose pipe and check center length. Keep the shielding; do not remove it to hide a routing error.
Step 9: Make One Final Alignment Pass
Check every joint and hanger with the full system supported. Tighten from the turbo connection toward the rear, using the right hardware specs. Stop if the front pipe shifts as the rear is tightened.
Troubleshoot The Extension, Rear Option And Heat Shield
| What you find | What to check before changing parts |
|---|---|
| Center extension looks too long | Seat the front and rear hangers, measure actual insertion, and mark only the plain end for trimming. |
| Tailpipe will not engage both supports | Loosen the adjacent joints and fit the supports together with a helper. Do not tighten one mount and bend the other into place. |
| Spare-tire shield touches the pipe | Rotate the loose tailpipe and check center-section length first. Keep heat protection in place. |
Final Check: Measured Length And Heat-Shield Clearance
- Front route: The downpipe and intermediate pipe follow the illustrated route without an unexplained extra section.
- Extension: The rear supported pipe is seated before marking length; each actual slip-joint insertion is counted once.
- Center option: The installed muffler or straight section is the section used for the length check.
- Tailpipe: The supported rear route clears the retained spare-tire shield after final alignment.
Before use, have the joints checked for leaks with the proper shop method. Do not run the engine in a closed space. If there is a new rattle, soot trace or loose support, let the exhaust cool and correct the cause. Follow the supplied hardware maker’s heat-cycle recheck instructions.
The link selects 2018-2019 / 4" Turbo-Back. If you want the muffler version, select 2018-2019 / 4" Turbo-Back w/Muffler, on that page. Confirm the matching center-section instructions before removal. View 2018-2019 / 4" Turbo-Back
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Before Use: Calibration And Leak Checks
Arrange the compatible calibration and any device or service your exact package needs before use. Exhaust fitting does not include ECU programming. Diagnose warning lights, reduced power or leaks before operating the truck.
Conclusion
Plan the lift work around the actual front connection and selected center section. Hang the rear measuring pipe before sizing the extension. Keep the heat shield and verify clearance as the full route is aligned.
For related parts on the same platform, browse 3.0L Powerstroke parts.
Match The F-150 Year And Center Section
Use the vehicle and option table above to match your build. The collection includes other pipe sizes and layouts, so keep the exact option name with your parts list.
References
- SPEtuner: "ES09033 illustrated installation instructions." Available from SPEtuner installation PDF.
- U.S. Environmental Protection Agency: "EPA Fact Sheet re Aftermarket Defeat Devices and Tampering." Available from U.S. Environmental Protection Agency.
- Cover photo: "Kevauto: "2018 Ford F-150 Crew Cab front 5.26.18.jpg — CC BY-SA 4.0. Layout added; vehicle photo retained. https://creativecommons.org/licenses/by-sa/4.0." Available from Cover photo: Kevauto.
FAQ
Q: Does This 4-Inch Guide Cover A 2020 F-150?
A: This guide covers the 2018–2019 F-150 3.0L. A wider date range on a reference cover does not establish every later truck or product option.
Q: What Changes Between The Muffler And Straight Versions?
A: The center section and its installed length may differ. Fit the actual section and supports before measuring the extension.
Q: When Should I Cut The Center Extension?
A: After the front and rear sections are supported in their mounts. Measure the gap and add actual slip-joint engagement at each end once.
Q: Can I Follow The 3.5-Inch F-150 Guide Instead?
A: No. That kit keeps the stock muffler and uses other mid-pipes. The rear layouts are different.
Q: Do I Need A Lift And A Helper?
A: The PDF calls for a lift or hoist and at least two people.
Q: What If The Tailpipe Hits The Spare-Tire Heat Shield?
A: Leave the joints loose and check tailpipe rotation, hanger seating and center length. Retain heat protection and correct the route before tightening.
Lars
Diesel Performance Engineer | 15+ Years Experience
"Empower Your Beast: Run Cooler, Pull Harder, Last Longer."
