i checked other threads i thought could help me but didnt find what i was looking for.

my car is a 1995 camaro LTi with the 6 speed tranny. here is the problem:
when driving, part throttle, the engine will seem to buck a little bit. this is most noticable 5th gear at 60mph with cruise control on. it has always done it if the RPMS are too low and i push the accelerator in too far.. but recently it has started to get worse and do it at normal driving RPMS and speeds.

so today i changed out the air filter cause i knew it was due time. also grabbed some MAF cleaner and cleaned it out a little bit. drove it a bit seemed to fix it but didnt last more than 30 miles today until it acted up again.
the car will drive fine when i get into it. floor it and the thing will still move.. however it doesnt seem as fast as i am used to.

parked the car about 30 minutes ago and turned the stereo off. let it idle in the driveway and noticed a bad sound. like gravel rattling around in the exhuast (my little brother used to throw gravel in the tailpipe). so i get out to inspect and notice the sound is coming from up near the engine. pop the hood and the sound is coming from the bottom of the engine i can hardly hear it from up top. so i look under and seems to be coming from near the cat convertor but honestly i didnt search for too long figure id heard enough.

does anyone know what could by my problem? i remember reading all the time when i had a thunderbird SC that sound is somethign to do with having a supercharger and using low octane gas and its the knock sensor.. could this happen to my stock LT1? its not supercharged so i dont think its "pinging" (what they called it at sccoa.com)

car has 120k on it and in the last 6 months have replaced the radiator, heater core, water pump, thermostat, EGR valve and piping, and then general maintenance (except spark plugs havent been done yet.. would this be my problem possibly?)

any help would be great guys. i love this car but i swear im ready to give it away for pretty much anything. just frusterated and want something i can drive without any problems.

 

cat is bad. on my old camaro i had an exhaust rattle and the piece inside the cat had broken and was rattling around. to check it just unbolt the exhaust where it meets the cat and look in there and see if it has broke or not. you need to change the plugs too if they also have 120k on them

 

x2..my old camaro would buck also,it was night and day when i removed it,felt like a gained 100hp.from it being clogged it would cause alot of back pressure and whn i floored it,it would just bog down and almost die becuase of the motor forcing all the pieces back towards the exhaust pipe and cutting off all the flow.

 

Is the noise intermittent? My car has a similar noise, but it happens every once in awhile, not constantly.

 

it sounds sure enough like a clogged/broken catalytic converter. My friend had a 1995 trans am and it had a cat do this, only his got worse, clogged and became a glowing cherry red, this is how he found out it was bad. gutted it, sounded and performed 100% better, whaaaaaaat a difference maker it was, if nothing else, you'll like the suddle deeper tone you'll get from your exhaust

 

I had a cat clog up once, got clogged so bad I drove 20 minutes to my shop and sprung 3 oil leaks along the way. Car barely made it. My guess is all the back pressure pushed oil through the seals. Busted the front main seal, rear main seal, and caused a leak from the low oil sensor. Clogged cats can do a lot of damage if you let them get bad.

 

i agree on the cat. mine got so bad in my v6 automatic that when i would push teh gas in it would lurch and stall like someone who was first learning how to drive a manual.

for a little self assurance....grab a screw driver or some other long metal thing and with the car running use it as a stethescope to find where the noise is comming from. Start with it on the cat (thank god us 95 guys only have one) put one end ont he car and hold the other to your ear and listen. If the sound is really loud then that is where its comming from.

on a side note, not that it seems probable, but when I was at the drag strip and blew my clutch to peices it sounded like sand and pebbles in the engine. Thought I blew the motor for a moment, but then i realized it didnt sound like a metallic grind or anyhitng. Now when I did that the whole thing was gone and destryoed there was no driving home or anyhitng. But would it be possible for you to have maybe torn a few peices of your clutch apart? Im not sure on this part thou so go with waht the other guys are saying

 

i do abuse the clutch a lot but it normally heats up and starts slipping i dont think it blew at all.. its too soft.

worried about driving the car to work tomorow ill have to bring some tools home and gut the cat ASAP. hmmm

 

Yea like i said man, if you blew the clutch it would probibly have totally obliterated to be making that sound, but that was jsut a thinking theory kinda thing. In eithercase gut that cat, it does nothing for ya but slow you down! hah