Fiat 124 Exhaust Installation

Installations instructions for MonsterFlow intakes, Big Brake Kits, shocks and more.

Fiat 124 Exhaust Installation

Postby Ryan @ GWR » Thu May 11, 2017 1:38 pm

2017+ Fiat 124 RoadsterSport Exhaust Installation Instructions
Good-Win Racing LLC Copyright 2016

These instructions cover the following RoadsterSport Fiat 124 items:
Muffler Delete, Midpipe & Cross-over pipe

Text only for now, will be updating with photos over time.

Difficulty on a scale of 1-5 (where 1 is beginner plug and play install and 5 is an engine swap)
Muffler: 1 (Just got your first set of tools? This is a good project to get your feet wet with)
Midpipe & Cross-over pipe: 3 (Requires working by “feel” & some specialty tools)

Tools Needed:
Soap & water in spray bottle
Socket set (10mm, 12mm, 13mm, 14mm, 15mm)
Bolt penetrant spray
⅞” Oxygen sensor wrench with flex head
Small flathead screwdriver
5 /8” open ended wrench
11/16” open ended wrench

Installation steps:
Full exhaust combo (Muffler delete, Midpipe, Cross-over pipe): Follow all steps 1-38
Muffler delete ONLY: Steps 1, 5, 6, 7, 27, 28, 35

The rear brake should be set and the car in gear and the car should then be safely raised and supported on a lift or with jack stands on a level solid surface (never work under a car held up by only a jack!!!).

1. Remove the plastic cover on the underside of the car just ahead of the rear right tire. There are 3 bolts and one plastic clip. 10mm socket for the bolts and a small flathead screwdriver for the clip.

2. Remove the X shaped brace from the bottom of the car. 4 bolts, use 12mm socket.

3. Remove the cross-brace from the bottom of the car. 4 bolts, use 12mm socket.

4. Remove the engine cover from the underside of the front subframe/engine. 9 bolts, use 12mm socket.

5. Spray rust penetrant on the four midpipe bolts: the two that join the muffler to midpipe and the two that join the midpipe to cross-over pipe.

6. Remove the two bolts that join the muffler to the midpipe. Use 14mm socket.

7. Spray soapy water on the four rubber bushings that suspend the muffler from the hangers on the car. Then remove the rubber bushings from the muffler’s hanger rods. Leave the bushings attached to the car. We like to use a specialty tool for removal as shown in the photo, but with the soap and water to lubricate things you can remove these by hand. It can help to have a second person hold the muffler up to prevent it from falling while you remove the last bushings. With all four bushings removed from the muffler, remove the muffler.

8. Spray soapy water on the single rubbing bushing that suspends the rear of the midpipe. Then remove the bushing from the midpipe. Leave the bushing attached to the car.

9. Remove the two nuts and springs that join the front of the midpipe to the cross-over pipe. Use a 14mm socket. Then remove the midpipe from the car.

10. Going back to the studs which you just remove the nuts and springs from, now remove the studs from the cross-over pipe’s flange. The studs have a short section with a hex for a wrench/socket. Use a 13mm socket.

11. Spray rust penetrant on the base of the oxygen sensor as well as on the 2 studs that join the top of the cross-over pipe to the downpipe. These are all tucked up against the side of the engine below the turbo and it is a tight space.

12. Loosen the nut for the bracket that holds the tail end of the cross-over pipe. Use a 13mm socket. Do not remove the nut yet.

13. Now disconnect the oxygen sensor’s wiring from the car. The wiring is fixed in a few places. The first location is via a small bracket attached to the downpipe. Remove the nut here with a 10mm socket or wrench, whatever you can fit in that space.

14. The next locations are hidden by the plastic wheel well liner in the front left wheel well. The majority of the liner can be left in place, only the lower rear portion needs to be released so you can pull the liner away to reveal the wiring. There are 3 plastic clips holding the liner to the car at the bottom/rear of the front left wheel well. Remove these by using a small flathead screwdriver to pop out the center portion of the clip, and once the center is out the outer portion can then be removed.

15. Pry the lower back portion of the wheel well liner back to find the oxygen sensor wiring’s connector and 2 plastic clips holding the wiring in place. Disconnect the connector and remove the two plastic clips.

16. The final location where the oxygen sensor wires are fixed is on a bracket attached to the left engine mount. The plastic clip itself is nearly impossible to reach, so skip that and instead remove the metal bracket from the engine mount. There is one bolt, use a 10mm socket.

17. With the oxygen sensor’s wiring fully disconnected, now remove the oxygen sensor from the cross-over pipe. Use a ⅞” flex-head oxygen sensor wrench.

18. Remove the two nuts that join the top of the cross-over pipe to the downpipe with a 12mm socket. Because these are tucked high up next to the engine we’ve found it easiest to do with a very long socket extension or series of extensions so that the wrench handle is lower than the underside of the car.

19. Remove the bolt from the cross-over pipe bracket that you loosened previously.

20. Remove the cross-over pipe.

21. Installing the new cross-over pipe
Fit the new cross-over pipe in place and loosely install the two nuts at the top and the bolt to the bracket. Then torque all three to 18-20 ft lbs.

22. Install the oxygen sensor in the cross-over pipe by feeding it through the front left wheel well. Fix the wiring in place in the same locations you removed it: one metal bracket to the downpipe (10mm socke), one metal bracket to the engine mount (10mm), and two plastic clips to metal brackets.

23. Connect the oxygen sensor’s wiring connector.

24. Install the supplied gasket on the outlet of the cross-over pipe. This usually takes a few taps with a mallet.

25. Thread the factory studs into the flange on the cross-over pipe’s outlet. Use a 13mm deep socket.

26. Install the front half of the midpipe on to the studs, then install the springs and nuts on to the studs and tighten the nuts down a bit to put tension on the springs. Leave this portion of the midpipe hanging for the moment.

27. Install the muffler: spray soapy water on the rubber hangers and install the larger portion of the muffler delete on to the passenger side hangers first.

28. Slip the included clamp on the smaller half of the muffler delete and then install that portion on to the driver’s side rubber hangers. With both halves now hanging, slide the clamp so that it is about half and half on each pipe. Lightly tighten the clamp with a 15mm socket.

29. Moving back to the midpipe. Slide the included slip joint clamp on to the front section of the midpipe with the flange pointed towards the passenger side of the car and the bolts oriented vertically.

30. Spray the blue polyurethane exhaust hanger with soap and water and then install the rear section of the midpipe by first attaching it to that poly hanger and then securing the rear flange to the front of the muffler delete. Use the supplied gasket and nuts/bolts at this junction. Use ⅝” and 11/16” wrenches/sockets to tighten. When tightening these bolts it can help to have someone hold the midpipe in place for you. Tighten to 25 ft-lbs.

31. Moving to the joint between the two midpipe halves, slide the clamp half way over each end, push the two pipes together as much as possible and tighten the clamp bolts with a 15mm socket to 30 ft lbs.

32. Tail pipe end alignment
Standing behind the car, determine if the two tail pipes are even. If not, you can rotate the left side up or down within the slip joint clamp. Once satisfied with the alignment, tighten the clamp bolts with a 15mm socket to 30 ft lbs.

33. Reinstall the plastic cover ahead of the rear right tire with the 3 bolts and one plastic clip.

34. Tighten the nuts on the springs at the midpipe to cross-over pipe connection.

35. Check for leaks in the exhaust system by starting the car and while it is running feel with your hands around the joints. If you do not feel air escaping, everything is sealed well. Be careful, the exhaust will warm up quickly.

36. Once satisfied that there are no leaks, reinstall the X brace under the car. Check to ensure there is clearance between the brace and the midpipe. If necessary, you can adjust the clearance by loosening the slip joint clamp and pressing up on the midpipe while retightening it. If clearance is still an issue, you may need to shim the brace down by placing washers between the brace and the chassis.

37. Reinstall the cross brace under the car.

38. Reinstall the lower engine cover underneath the engine.

You're done. Enjoy!
Ryan @ GWR
Posts: 212
Joined: Fri Oct 17, 2014 11:37 pm

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