Misfire

[the_dingman]

So, I've got a misfire, only really noticable at idle. I can hear is missing every few seconds, and it's uneven. I do have an exhaust leak (though small) on the outlet of the cat... Is that a possible cause of a sound like a misfire?

Where do I start troubleshooting?

 

[88T4RE]

I dont know for sure but I was driving my mr2 around the other day without the exhaust on and no cat. just a header and it backfired a few times so the hole is most likely the problem...:flamethrwoer2:

 

[turboSR5]

Vacuum leaks come to mind as well as exhaust leaks. Have you checked your timing recently?

 

[the_dingman]

I did a front end rebuild (timing chain, water & oil pumps, TC cover, belts) a few months ago with a friend who is a professional mechanic. We set the timing and adjusted the valves.

I'm pretty sure the vacuum lines are ok... But the exhaust could be the problem?