If your car's exhaust leaks a lot of fumes, hisses, chugs, or makes a roaring noise, the exhaust system might need replacing. You may also notice visual damage, including cracks, extensive rusting, or misalignment. Replacing your car's exhaust system requires a little mechanical or technical knowledge, but is reasonably easy to achieve if you have the right tools and follow some basic steps.
Tools You Need for Replacing Your Car's Exhaust System
You need a car jack and axle stands to raise the car completely off the ground and hold it safely and steadily. Safety glasses protect your eyes from dust, debris, and metal bits. To remove and replace any socket fixtures, keep a socket set on hand, along with lubricant, such as WD40, to help with degreasing and loosening stubborn fittings. A Dremel rotary makes the job much faster and simpler. You also need a flat screwdriver for removing and replacing screws, and a stiff wire brush for removing rust, corrosion, old paste, grease, and debris deposits from the threads. Finally, to safely replace the exhaust system, you need exhaust paste.
Preparing to Replace Your Car's Exhaust System
Raise your vehicle on a car jack and position your supporting axle stands. Leave yourself enough clearance to get under the vehicle and access the exhaust system. Wearing your safety glasses, examine the exhaust system to identify whether you only need to replace from the catalytic converter backwards, or the cat-back system, or you need to replace the entire system. Remove all the clamps holding the exhaust to the mounting and the two exhaust sections to each other. Use WD40 to loosen the fixtures. Next, remove the old pipework using a rotary tool with a cutting blade to cut a line where the larger pipe slides over the end of the smaller. Make sure you do not cut deeply enough to touch the smaller pipe beneath. Remove the pipe and any seals, rubber hangers, or gaskets. Finally, prepare the mounts, gaskets, and any other parts you are not planning to replace by scrubbing them with a stiff wire brush to remove any debris, grime, or corrosion, as this helps to ensure a tight seal with no leaks.
Installing the New Exhaust System
The installation is reasonably easy. Fit the new pipework carefully, replacing the rubber hangers and gaskets, before sliding the larger end over the smaller. Before you clamp the join together, apply a liberal coating of exhaust paste, such as Holt's Fire Gum, as this creates a tight, heat-roof seal that prevents fumes and gases escaping. After application, clamp the joint shut, then replace all of the screws, sockets, and other fixtures. Test the system by briefly running the engine and check for leaking fumes.