Fix exhaust leak undetectable without stethoscope?

[WillsYoda]

I brought my 98 toyota avalon to the local mom & pop exhaust place and they fixed a large exhaust leak. Afterward with the car running they thought all was well. There are no visible or audible leaks... except they decided to put a stethoscope on the exhaust manifold and detected the tiniest leak in the exhaust manifold gasket.

They said the leak was so small that it can be ignored for now, but (a) they could fix it if I wanted and (b) it should be fixed if it becomes bigger as evidenced by either a relevant engine code or a visible or audible leak without a stethoscope.

My question is "Is this true, can I just ignore this tiny exhaust manifold gasket leak as long as it doesn't get bigger or cause a code?"

 

[ag_ghost]

I have a friend with a mid-90s Civic that has a cracked exhaust manifold that he's managed to keep running and smog checked for the past few years. But IMHO, I think he should fix it. There are only a gazillion replacement parts for it on the market which I suspect holds for your ride as well.
Kevin

 

[KingCake]

I don't know how they heard a manifold leak with a stethoscope...you put one on any exhaust manifold and you will hear exhaust...

Look for soot around the gasket.

 

[DoubleWasp]

I've done it before on plenty of Jeep 4.0's with cracked exhaust manifolds, and plenty of V8's with leaky exhaust gaskets.

It takes some real searching (20 mins avg) but can be done.