Exhaust welding

[scottmk1]

Hi, I need to refit the standard exhaust to my RS4. The standard exhaust was modified by means of chopping out the centre section and fitting two straight through pipes.
To refit the original centre section I will need to weld the original back boxes back onto the centre section, and I would want to at least tack them with all parts mounted so that I get the alignment correct.
If I weld them with the parts mounted on the car would disconnecting the battery be sufficient to stop any ecu's getting fried or would I need to do anything else?

[Terry1948]

you could try putting a collar over the joints and not weld.

[scottmk1]

Thought of that and there isnt enough pipe left coming from the centre box for a collar to get hold of

[b7rs4saloon]

Slip a collar over the piece with the stubby amount of pipe. Weld it on then clamp the other section to it....

[Madmonkee]

Res an old thread...
Question, was there any noticeable noise increase by doing this? Power losses? I like the noise of the standard exhaust just yearn for slightly louder version of it. Wondering if it's worth having a dabble with the standard zaust?? Front and back boxes out? Or am I just wasting time and money?