I have a slight idle problem, it will go up and down from 750rpm to 1500rpm when at idle. When I rev the engine there is a pretty bad exhaust leak coming from the stock exhaust manifold. Can an exhaust leak be known to cause an idle problem?

 

^^

 

It should not affect anything, unless the leak is above an oxygen sensor.

Usually an idle problem is a bad sensor or vacuum hose.

 

The leak is before the O2 Sensor. Where the four exhaust runners merge into two.

 

Then yes, the exhaust leak is prob. the cause of your idle problem.

 

OK, thanks.