i have an 89 iroc with a lo3 (305 tbi) drove it to st.louis yesterday and it did fine all the way there, and about an hour of the drive home.
but i was running about 65 and pulled out to pass a slower car, when i did, it had no power, in fact, the more pedal i gave it, the slower it went. i pulled off to the side to have a look, and saw that the emissions "manifold" had burnt a hole in it. i patched it up so it wouldn't start a fire (it already started to melt the air conditioning box a little) when i went to take off, i couldn't get it to go over 50.
when it is first started now, it will tach 5k with out any trouble, for about 5 seconds, then drops off fast, and wont go over 3k without a load or 45 mph driving ... idles ok but sounds like it may be blowing some exhaust out where the exhaust manifold fits to the y pipe when you give it throttle. also going up a small hill on a back road, it put off such bad gas fumes, i thought i would have to pull over cause it was burning my eyes so bad, and i can see the injectors putting out fuel (so it seems to be getting enough gas). it is all factory, except for the things i had to do to plug the hole, even still has the cat on it ... i was thinking that could be the trouble, but would like any info you guys may have ... i need some help for sure

 

Sounds like your catalytic converter is plugged

 

does sound like a plugged catalytic converter.

 

took it off from the cat back today ... big chunk of the honeycomb broke off, and had been shaped just like a plug the size of the outlet of the cat ... broke a bolt getting it off and cant get it out yet, burnt 3 wires when the hole burnt in that manifold, but it will tach up now and hit 75+ without any trouble though ... lol ... thanks for the input guys

 

Hi ihave a 85 camaro tpi just had the motor rebuilt its a 400 sbc ran it out yesterday fir about an hour and it started to sputter and wouldn't go past 40 and everytime i gave it gas it would cut out i dont have catalic converters on it could this be a electric problemor fuel problem or ecm going out

 

i would check your injector wires, and fuel filter, then wait till its dark, start it up and inspect your plug wires (to ess if you can see any sparks being thrown) make sure your ground strap didn't come loose and i would start a new thread about your problem, so more people will to see it and be able to help you more than i

 

Thanks bud i appreciate the help