Wondering if anyone has had problems with there Cat. as well, and what are some of the symptoms.

I noticed a rattling when I first started the car but that went away as it got warmer.
but I also a whistling noise when my car started to boost past 35kpa (about 5psi),
the boost would also build up much quicker then usual, and I just wouldn't get the power that it was supposed to.

anyways I'm without a my car for a few days (waiting for the cat to be delivered), at least there giving me a rental.

but what would cause something like this to happen.

 

yup i had the same exact problem 18,000 miles on the car and it just went out on me... like it started as rattling then it was the rattling then the whistling noise went to get it checked and they replaced my cat

 

Get it fixed brfore it goes.. they blamed mine on me and I am still paying for it

 

wow the dealer didnt cover yours... what did they tell you that caused yours to go r33p3r ?

 

mine is sitting at the dealers as we speak, they got me a rental while I wait for the Cat to come (it's on Back order).
so the whistle is being caused by the cat as well. Thank god I thought it was a seperate problem.

I'm at about 22000miles

 

yea had so many problems with my car... should have listened to my parents when they said that i shouldn't buy the first batch of cobalt's to wait until the '06 came out

 

they said i ran leaded fuel inm it, and it caused it to seize up. it made all the gaskets from the cat forward go, and they didn't fix any of it

 

i had a rattle and thought i fried my cat cuz as soon as i got stage 2 and hammerd it i started hearing a rattle, turns out the last hanger was loose on the exhaust and during hard driving the metal would hit metal and that was the issue so we moved the hanger and put rubber around it so there is no chance of anymore rattleing, gonna grab some poly hangers cuz stockers have so much play its not even funny, sorry bout yer ride ed, atleast its covered. I have heard and dont quote me if you hear a ticking on yer stock exhaust thats one of the signs of a potentially bad cat, when i got my gmpp sport the ticking went away, this isnt fact its jsut what ive heard but i dont recall anyone with the gmpp or any aftermarket exahsut having cat issues, i could be totally wrong but its something to think about.

 

I don't know I haven't had anything other problems until the Cat. other then the shitty Rotor whitch are being replaced with power slots as soon as I get my break pads.

othere the leaded feul WTF! what else could have caused this? not my cams right

 

they still sell leaded fuel ?

 

thanks but my babe will be just fine, it's being delt with before it's a big problem, besides I'll probably be driveing a cobalt as my rental anyways

 

that's was my thought, how could they give you that reason

 

i dunno, nowhere i could get it, even if i wanted to use it

 

so any other ideas as to what might have caused this?

 

overboosting or using the bypassmod.

 

how many times have you used the bypass mod ed??

 

3 times total, but I was haveint symptoms even before I tried it
and the longest time I used the mod was when we went to tthe Cayuga, I got in 10 runs total. so probably 20-30km total. couldn't be more then that.

 

at what point are you considered to be over boosting?
aren't people hitting 17psi with the stage kits

 

yes, but if your stock any more then 12.5 is overboosting. thats what I think happened to mine

 

it shouldn't make a differance if your stock or not.
if the cat will start to go if your hitting 17psi, then people with the stage kits should be watching out for there cats.

I know that when I had my cams done, I was able to hit 17psi but only with the by-pass mod. otherwise after 15psi it would blead off back to 12.5psi

 

what about people with the intense stage 3 kit, havnt heard any probs with thier cats from them and im sure there boostin over 12.5., and if there have been probs i probably missed that, feel free to correct me if im wrong.

 

I'm hopeing it was just a bad Cat. because I have one of the first few aswell.
but if it's something I was doing or added, I wanna know so I can fix it.

a couple of the codes that showed where, P0101, and P0300

 

a bad cat is possible, alot of the 05s have experienced this, but for you it could be a few things and it sucks cuz u cant really be sure, cams maybe?? boost bypass?? stock exhaust causing problems??? or just a defective cat, hopefully the new one dont give u probs. what are those codes again??

 

P0101 Mass Air Flow (MAF) Sensor Performance ECM, PCM
P0300 Engine Misfire Detected ECM, PCM

and a couple others but the service advisor couldn't remember

I'm guessing the second one happened when the engine overboosted and caused my car to go into limp mode.

the over boosting hast to have something to due with the Cat. be blocked

 

I would seriously bitch to GM about that... they don't even sell leaded fuel in the United States or Canada... and I don't think you drove to Mexico in that car... what they told you is total bullshit... I'd have that service manager's head on a plate.