Ford 2003 Mustang Workshop Manual page 2953

Installation
1. Position the LH and RH dual converter pipe.
Snug the converter-to-manifold nuts.
2. Position the muffler and install the dual converter assembly nuts. (RH shown, LH similar.)
3. If necessary, position the sleeve and clamps. Tighten the clamps to 55 Nm (41 lb-ft).
4. Tighten the four converter-to-manifold nuts.
5. Connect the two upstream RH and LH heated oxygen sensor connectors.
6. Connect the two downstream RH and LH catalyst monitor sensor connectors.