I have had a tune done by madz28 and put new o2 sensors in and the car still runs rich, i do have two very little maniflod leak which might be some of the problem. The car in the morning is running rough to. Also the car in town, driving it slow then giving gas fast it back fries though the intake it also back fires badly if you get in the throttle then get out then get back in to it again. Any comments, Thanks !

 

Yep, definitely sounds like you're running rich
You didn't give much detail on your two manifold leaks though....intake or exhaust manifolds? What's your idea of a "small" leak?

Most common causes for these cars running rich are exhaust leaks before the O2 sensors and vacuum leaks after the MAF. Aside from that, fouled or worn spark plug(s) and/or burnt or otherwise bad wire(s) are also common causes.

I'm troubleshooting the same thing on mine right now (among other things ) and found all three! Loose spark plug, leaking slip joint on my Mac headers and a disconnected vacuum line going to the intake. Best thing to do is just remove as much "in the way" stuff as possible and take your time visually inspecting the engine bay top and bottom from as many angles as you can. That's how I've found most of my problems in the years I've been screwing around with F-bodys.....

 

How can you tell you have a manifold leak, what sounds do you hear?

 

You don't have any internal mods and the tune does not change anything from stock to cause you to run rich. Unless you're running regular gas, I would say your opti is going bad. You do need to fix all leaks before doing anything else though.

 

exhaust maniflod gasket are the ones that are leaking sorry abouyt that. So when madz28.com does the 91 tune what does it tune ???

 

I also have delteq ignition so can the sensor and eye of the opti spark slowly go bad ?