Will exhaust leak cause bad idle?

[thornton22050]

Hey guys i have a major exhaust leak where my cat meets my downpipe. it almost like theres no gaskets in it or one side is missing the bolts, thats how big it is. anyways my idle is bad it sounds like i have aggresive cams real lumpy idle. do you think my bad idle is caused by the exhaust leak

 

[ILLiCliPSE]

an exhaust leak will make more of a hissing noise than anything. I have a small exhaust leak where my dp and catback meet i believe, and it makes a hissing noise. it doesnt cause bad idle on my car. mines always at 750rpm just like stock.

 

[Locke]

as long as the exhaust leak is after your upstream o2, it would not effect performance.

I would check the alignment of your cams. If your tensioner is bad, or was set incorrectly (pulley), you may have jumped time. Causes a very lumpy, low, sometimes erratic idle. Also can cause valve damage if it gets worse. If the silent shafts/oil pump were not aligned correctly, this could cause some lumpiness as well.

A lazy crank sensor could also cause it.