How to repair a leaky exhaust pipe with a butt splice

     When a big leak developed at the flange joint between the catalyst and the resonator on a Pontiac Grand Am, at first it looked like the entire exhaust system might be needed. It could cost hundreds of dollars to replace everything from the manifold back to restore it to the original configuration. I thought of other options. Then it hit me. I could cut the leaky flange joint out with an angle grinder or reciprocating saw and replace it with a butt splice. Hooray. Less than ten dollars bought a reliable fix.

This flange has got to go

                                                      The job at a glance

• Tools: Angle grinder, reciprocating saw, tape measure   
• Materials: exhaust pipe sealant
• Parts: Butt splice, 3 inch, pipe clamps    
• Cost of parts: Splice: $3.50 Clamps 5.25 for two
• Time: 1 1/2 hrs.

1) Take some measurements to determine the size of splice needed. We will need to know the outer diameter of the old pipe and the length of splice needed to fit the pipes together. 

2) Remove the bad section of pipe with an angle grinder, reciprocating saw (such as Sawz-all), oscillating cut-off tool (such as Dremel) or hand saws. 

3) Clean up the cut end of the pipe with a file. Remove loose material with a wire brush and clean with solvent.

4) Purchase splice and clamps and test fit. I had to trim the splice to make it fit right. It may be necessary to remove the downstream pipe from hangers to fit. 

I trimmed one end of the splice for best fit

5) Apply a layer of pipe sealant to the outer mating surface of the existing pipe. 

6) Install the splice. Confirm there is maximum overlap at both ends of the pipe to be repaired and the splice. 

7) Clamp the splice into place and bolt down securely.

Nice and quiet and very attractive

8) Test the repair for leaks.