Rattling/Loss of power/Stall
 

Hey guys, this summer I have been experiencing a unique issue.

First off I have a 2004 GT A/T. 49k miles.

I have about a 3 mile drive, straight line to work, sometimes, when taking off, and pushing the card hard (IE redlining it) in first gear, around 6k RPM's It starts to lose some power, and then there is a awful rattling/popping/shacking noise. It almost sounds to me like the exhaust is coming right from the engine, although, it is not SUPER loud.

Now, today, I drove to the next city over to grab some new glasses. When driving I experienced the same problem, and it carried over into second gear till around 5k RPM's, then I would let off the gas, and let it shift. The loss of power in second gear is considerably more than in first gear.

On the way home I decided to take the highway. Staying around 75 MPH wasn't the easiest thing to do, and it just seemed like I had to give it way more gas then required.

Once I got home, I put it in neutral and reved it 6-7 times keeping it at 6k RPM's and above. No loss of power, no noise.

So I decided to take it down the road to 7-11. Now, while sitting in traffic it actually stalled. It has never done this before, and I was quite shocked that it did. Although, it did start right back up, thank god.

I decided my trip was over, and decided to come home. On my trip home I had a huge power loss, feeling like it would just quit on me at any moment of trying to accelerate from a dead stop. Once I got home, I attempted to rev it, but it was VERY slow to come up in RPM's.

So my question is, what do you guys think is my problem. I'm going to call the dealership and ask him, but I would LOVE to know your guys opinion on this.

Thank you very much in advance,
-Vince.

Tonight, take your car for a spirited 1-2 mile cruise around town. Park immediately and look under the car, see if there's something glowing.

If so, your cat converter is clogged.

Or if you're mechanically inclined, jack up the car and disconnect the cat, look inside with a flashlight to see if the mesh is all still in tact.

Yup, sounds like your CAT is dead. After you check your CAT, if it is indeed dead, take the car to the dealership and they will replace it for free. By federal law, you have an 8year/80k mile warranty on your emissions system. After replacing the CAT, be sure to replace your Coils, Plugs, and Wires. If they weren't shot before the CAT died, they are now. Most likely, they went bad and killed your CAT.

Sweet, I'm gonna head out and jack it up and check it out.

If it is clogged, how would you suggest cleaning it? Also, if it was broken/brittle or what not, my first instinct will be to just empty it out, and put it back on empty.

Ideas?

Disregard my last post.

You make me so happy, I really hope this is the problem. Also, thanks a ton for the free cat tip, really Appreciate it. I post back my results in a hour or so when I get done outside.

You can't "fix" it. You have to get it replaced. The dealer will replace it for free. If you gut it out then you are not going to pass emissions, so you will need a CAT for at least passing emissions when you get tested. The CAT alone costs around $1,800, so you want to take advantage of getting a new one for free while you can.

Cool deal. Good luck :)

Have you changed your plugs/coils/wires in the 49k miles you've had the car? Just curious, if not take note that this should be done every 25-30k miles. This may be the culprit if your cat is clogged.

That way you can avoid future problems

also I know this is off topic, but you should drive the long way to work to ensure your getting the cat completely warmed up on your drives. Short trips can cause water build up in the oil. An easy way to check this is on the next oil change if your oil looks a tiny bit milky. Again I know this is off topic, but its really hard on engines if you don't warm them up completely including the cats. The cooling of the engine causes condensation and if you don't have the car warm enough it wont cook off the old before you build new moisture.

No I have not changed coils/spark/wires. I know I should.

When I looked under the car I found a few things, for one, rust, two, bolts, with springs.

I don't want to take the springs off, because I have no clue how much resistance they have, and I am working by myself in a cramped area, if I can't get them back on I'm pretty screwed.

Attachment 255685

Attachment 255686

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If anyone knows about the bolts, that would be awesome.

Took it out for a spin tonight, probably about a mile drive or so. I didn't want to go to far, or drive it to hard, just in case something did happen.

Looked underneath when I got home, no glow, at least that I could see. When I did start it up though there was barely any exhaust coming out and it smelled horrible. That just leads me to think more and more, you guys are right about the cat.

I am 100% sure its the cat. The fact that this car is even running on original plugs/coils/wires shocks me.

REPLACE COILS/PLUGS/WIRES WITH CAT REPLACEMENT.

Do not procrastinate that, or you will toast another cat.

Bring it to a dealer, you are still under warranty; do not make any voluntary mention that you have neglected to replace the plugs/coils/wires at 30K or they will more than likely blame this issue on that.

Aight, can do for the keeping quite thing. Since I can not get into the dealership for another week, I'm going to take it to Midas tomorrow, just to be sure, and will be driving my truck for the mean time.

Ill post back with what Midas says, and I'll do some research on the DIY plugs/coil/wire replacements.

theres plenty of DIY on the plugs, coils, wires. Its actually pretty easy.

I recommend not driving on it too much. My buddies RX8 almost caught on fire when his cat was clogged (carpet on passenger side melted) so be careful. Remember, your cars constipated right now, lol.

Oh yeah I don't plan on driving it much, and taking it slow when I take it to the shop. I really hope this is the problem, and I can't wait to see what it will preform like with all the new parts.

At midas right now, the cat is good. So, guess ill grab some wires/plugs/coils and see what happens.

What did midas do to check your cat? There is no way that thing is good

Hell, that damn thing is even rusted through!

They drilled in the exhaust line, and put a air pressure sensor in there, then revved the car. Said it was all good, and I def trust the guy because he is a family friend.

The other thing is, when I was driving to Midas, I had none of the problems I listed above, which makes me wonder whats going on. I still have a appointment to get it checked up at the dealership next week, so that will hopefully provide promising results.

Your cat is burned through, there is no way it's good. No offense but your friend is wrong. It's evident by the pictures.

Take it to the dealer, avoid driving until then.

Have them disconnect the cat and look inside it with a flashlight to see if the guts are still intact. This is the best way to actually test it.

Yeah I asked him if he could disconnect it and look inside, but he said there was no need, since he was using his method. Also, the fact that it was free, and he slid me in on his break I took what I could get.

I really appreciate your guys opinions/help a lot on this too, just so you know.

You def must have blown through the CAT. Did you ever hear any rattling in the exhaust? The pieces will sometimes rattle around on their way out the back.


Edit: You said you heard rattling in your original post. Dude, that rattling was the internals of your CAT working their way out the back of the exhaust.