I've just had an emissions test done at my local garage and I couldn't get lambda down below 1.2 despite turning the mixture screws out by over 2 turns. The mechanic suggested that I had an air leak somewhere and that a tube held up to my ear could help me find it.

If I hold the tube to where my 4 exhaust pipes go into 1 then I can hear a the resonant noise of the rubber hose I am using. If I move it round away from the noise then the pipe goes quieter.

Does these mean that the welding on my (new) exhaust is leaking?

Given that the pipes all touch each other, how do I seal the leak?

weld it with a more tradional system..
an system wich only need heat and then the material (what you applies) walks on his own...

i would try to weld it with autogeen..
because it will be the only way to get the think sow hot that the material you add goes where the holes are.

also you could try do it from the inner side..but offcourse i don't know the shape totally.


Tks

[Edited on 22/11/05 by tks]

The exhaust was supplied to me by MNR. I am no welder and so cannot weld it myself. I have to say that it looks very neat but then I can't see between the pipes.

I don't even know that the change in noise means that it is leaking. I've enver listened to an exhaust through a fuel hose before.

Look for soot around junction or blow some smoke over the join and see if it is being blown away from anywhere. Check your manifold bolts are all torqued up evenly and correct load. Joints are more likely to leak than a properly made welded structure.

it may be worth checking around inlet side for leaks as well.

Caber

Try holding a rag over exit of exhaust , any leak should show up.