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How to Install Roush 2015+ Mustang 2.3L-I4 Ecoboost Power Pack Level 2 on your Mustang

Installation Time

2 hours

Tools Required
  • 3/8” Drive Ratchet
  • 3/8” Drive Extension 3”
  • 15 mm Socket
  • Spray Lubricant (Soapy Water/Glass Cleaner)
  • Reciprocating Saw (“Sawzall”)
  • Marker
American Muscle
Shop Parts in this Guide

Original Exhaust System Removal

1. On both sides of the vehicle’s dual exhaust system, mark the LH and RH rear side of the exhaust pipes before they curve to the muffler as shown below, at the tangent of the curve.

2. Cut the LH and RH exhaust pipes at the locations marked in step 1 using a reciprocating saw with a metal blade. 

3. With the exhaust pipe cut, slide the hanger out of the rubber mount and remove the muffler/tip assembly from the vehicle.

NOTE: The disassembly process is identical for the left and right sides of the OEM exhaust. This concludes the disassembly process for the OEM axleback exhaust. Use extreme caution during installation. Torque all fasteners according to manufacturer’s torque values and tightening sequence. DO NOT use air impact tools to tighten fasteners on ROUSH Performance Products Exhaust Systems. Use of such tools may result in bent flanges or gasket contact areas leading to exhaust leaks which may result in serious personal injury or death.

RPP Exhaust System Installation

1. Remove any protective shipping covering from both the RH and LH mufflers.

2. Slide the provided band clamps over the original exhaust pipe, one clamp on each side (LH and RH). 

3. Insert the Roush muffler hanger into the mount at the rear of the vehicle, and then slide the new pipe over the existing pipe.

4. Slide the band clamp (94-0053/94-0052) over the joint in step 3 and torque the 15 mm bolt to 30 Nm.

5. Place the band clamp (10-0338) over the exhaust tip and slide the tip over the muffler. Torque the band clamp to 30 Nm once the tip is in position.

6. Check the exhaust system for correct clearance under the vehicle and also for tip alignment as shown below. If alignment is off, loosen the required band clamp, adjust, and re-torque the band clamp

7. Once the desired position and alignment have been achieved, make sure all band clamps are torqued to 30 Nm.

8. Before starting the vehicle, make sure to check all wires, hoses, brake lines, body parts, tires and any other components for safe clearance from the exhaust system.

9. Start the vehicle and check for any leaks. If any leaks are found, determine the cause (such as loose or incorrectly positioned clamp) and repair as necessary.

Congratulations!!! You have completed the installation of the ROUSH Performance Products, Ford Mustang Exhaust Kit. It is recommended that you save all parts removed from the vehicle during the installation of this kit.

2015 Mustang Ecoboost Cold Air Intake Installation Instructions P/N: 421827 (131523-9A600)


The following section will guide you through the removal of the stock components. Special care should be taken to label fasteners and parts that are taken off during this procedure since many will be reused.

1. Cover both fenders with fender covers to protect the vehicle fi nish.

2. Disconnect the battery ground cable.

3. Disconnect the air temp sensor connector as shown.

4. Loosen the clamp at the air box from the intake tube.

5. Release the two (2) latches holding the box lid to the lower box.

6. Remove the air box lid and 

7. Using the 10 mm socket, remove the bolt holding the air box to the inner fender. Retain the bolt as it will be used during installation.

8. Remove the air box tray and dirty air inlet from the vehicle.

9. Remove the three (3) clips shown on the inner fender to give the slack needed in the wiring harness.

10. Remove the clamp holding the air bypass valve hose.

11. Remove the PCV quick connect fi tting from the stock clean air tube.

12. Remove the clamp on the turbo inlet end of the clean air tube. Once the clamp is off, you can remove the clean air tube and air box from the vehicle.

13. Remove the steel bushing and two (2) rubber grommets from the stock air box. Retain these for use during installation.  

14. Remove the rubber isolator from the bottom of the stock air box tray and retain for use during installation.


1. Install the rubber grommet that was removed from the stock air box into the ROUSH air box (P/N: 131550-9A612), then insert the steel bushing.

2. Install the second grommet onto the air box (P/N: 131550-9A612).

3. Install the rubber isolator into the bottom of the air box (P/N: 131550-9A612)

4. Insert the dirty air inlet (P/N: 1315-9F763) into the air box (P/N: 131550-9A612).

5. Place the bulb seal (P/N: 131550-9C664) onto the top of the air box (P/N: 131550-9A612)

6. Insert the air box assembly into the vehicle.

7. Using a 10 mm socket and the bolt removed from the stock air box, attach the air box to the vehicle. Torque to 8 Nm.

8. Loosely attach the air fi lter (P/N: 131550-9601R) to the fi lter tube, leave the clamp loose so you can hide it once installed on the vehicle. Make sure the arrow on the fi lter is 90 degrees to the temperature sensor boss as shown.

9. Slide the fi lter tube assembly into the air box (P/N: 131550-9A612), making sure the sensor boss is pointed toward the front of the vehicle. Using a 10 mm socket, install the two (2) supplied bolts (P/N: W500224). Torque to 10 Nm. Rotate the air fi lter clamp to a suitable location and torque to 3 Nm.

10. Install the clean air tube coupler (P/N: 131523-SILCP) onto the clean air tube (P/N: 131523-9B659) using hose clamps (P/N: 5340, 5348). Tighten the inner hose clamp to 3 Nm. 

11. Insert clean air tube assembly between the turbo charger and the fi lter tube, tighten hose clamps to 3 Nm.

12. Install the PCV tube with the quick connect (make sure it’s fully seated), followed by the recirculation valve hose with the constant tension clamp

13. Remove the air temp sensor from the factory air box by twisting counterclockwise and re-install into the ROUSH fi lter tube (P/N: 131523-12B579) by twisting clockwise.

14. Connect the temperature sensor connector.

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