Drove to the beach last month and after an hour of highway cruising when we got off the highway the car was idleing really rough fluctuation and when when gas was applied to start moving it would bog but catch itself and cruise again fine.

the trans was on its way out so when i got home that day, it was doing the same thing after i got off the highway, parked it and got a new trans for it. while the trans was out i replaced spark plugs and wires, egr and gasket, cap, rotor, coil, and tourque converter.

when the motor is cold after sitting for a little it runs idles and moves fine after it warms up it goes back to the whole rough idle show.

while cruising its fine when at a stop the idle fluctuates so low that it wants to stall and sometimes does. It sounds like there is a miss and when i remove the injector plug for the #6 cylendar the idle gets better. (does that mean the injector is bad like stuck open?)

checked firing order several times
cleaned intake plenum when trans was out and egr ports.

 

car is a 1991 camaro 5.7 tpi

 

please tell me that you replaced the rear main seal when you had the tranny out

now, to your problem- it's an O2 sensor

I don't know how many your car has. My 89 has 1, my 95 now only has 2, my stang has 4

 

O2 is good i replaced it when i bought the car cause it threw the code and i only have one

 

I've had my 95 since December 2008. I replaced both O2's when I got it and have replaced them twice since then. Each time the vehicle ran better after replacement and there were no codes