Carbon deposits on exhaust tips

**CKramer** · 05-13-2007, 08:54 AM

Hey,

I've been plagued by my 2000 Camaro SS not performing up to par for a couple years now, and I've spent quite a bit of time/money trying to figure out what the deal is, and so far I've still had no luck. See my original post, Where'd my power go. In short, the symptoms I'm having are a substantial lack of power, and the car seems to really bog down and not respond well when I get on the throttle. It seems to run pretty smooth, though, no misfiring that I can tell. I've tried a lot of stuff to try and fix/find the problem, including replacing all the spark plugs, putting in new MSD plug wires, vacuum tests, fuel pressure tests, etc... And I still haven't found the problem.

So I was getting an emissions test done the other day (it passed), and the guys doing the test noticed what they thought was a "huge" amount of carbon deposits on the exhaust tips. I mentioned the car's problem to them, and they seemed to think (based on the carbon deposits and the symptoms) that I'm not burning all the fuel (this may be obvious, but I'm new and still learning). Now, I know my plugs and wires are good, cause I put them in myself (and I had the problem before I did that anyway). The guys at the shop told me an MSD ignition would fix my problem. But if I am in fact having a problem with ignition/combustion, would there be a better way to try and diagnose/fix it, as opposed to just throwing more spark in?

I've tried so much stuff to try and get this car running right, and I would be sooooo grateful if someone could help me figure out what's wrong with it. I know there are so many knowledgeable people here, surely someone has a pretty good idea about what's going on with my car.

Thanks in advance.

**LS1_TA_2002** · 05-13-2007, 01:59 PM

Got your pm. Looks like it's running rich. First, what mods are done to the car? If not too many try to load a completely STOCK tune into your PCM. Secondly, are you the first owner? If not, who knows what kind of things the previous owner did to it. Generally speaking, if your car is running this crappy on a stock tune the check engine light should come on. Does the check engine light come on, for a few seconds, when you first start the car? It should. Post back with the answers to these questions please.

**0rion** · 05-13-2007, 03:07 PM

No exhaust leaks in front of the O2's? AIR pipes or anything? What kind of filter are you running and have you ever had the MAF off the car for any reason? Have you tried cleaning the MAF? Bad O2's won't always throw a code but that's an expensive guess. Try swapping the front O2's with the rears. Check your local forum on the site and see if anyone near you has autotap or something else that will log the car for you. It should show up pretty quick in a log or at least get you started on track.
I'll give you an example. 2 summers ago my buddy was having trouble with his heads/cam vette. It was running like ass. I noticed his exhaust was sooted up which made me first want to look at the O2's. We got a log and sure enough one of his O2's was flat lining. The car never threw a code for it. Might not be your trouble but would be worth finding someone to log the car for you to at least rule the O2's out.

edit:
another thought. How many miles are on your car and are you still on stock cats?

**CKramer** · 05-13-2007, 04:05 PM

Originally Posted by LS1_TA_2002

Got your pm. Looks like it's running rich. First, what mods are done to the car? If not too many try to load a completely STOCK tune into your PCM. Secondly, are you the first owner? If not, who knows what kind of things the previous owner did to it. Generally speaking, if your car is running this crappy on a stock tune the check engine light should come on. Does the check engine light come on, for a few seconds, when you first start the car? It should. Post back with the answers to these questions please.

Thanks for your help on this.

The only mod is an SLP lid (aside from MSD plug wires and !CAGS). I have not done any aftermarket tuning, and I know the previous owner didn't either: would it still help to try and load a stock tune? If so, what's the easiest way to do that? I am the second owner, I bought the car with 20k miles, and fortunately, the first owner was very good to the car. He babied it, and didn't do any mods. It ran great when I bought it. Started noticing power decrease around ~40k miles. The SES light comes on at key on to verify, but it does not stay on when I start the car. Also, about 18 months ago I took it to a dealer with these complaints, and I believe all they did was hook it up to a computer (check for bad sensors, etc.?), but they found nothing.

**CKramer** · 05-13-2007, 04:13 PM

Originally Posted by 0rion

No exhaust leaks in front of the O2's? AIR pipes or anything? What kind of filter are you running and have you ever had the MAF off the car for any reason? Have you tried cleaning the MAF? Bad O2's won't always throw a code but that's an expensive guess. Try swapping the front O2's with the rears. Check your local forum on the site and see if anyone near you has autotap or something else that will log the car for you. It should show up pretty quick in a log or at least get you started on track.
I'll give you an example. 2 summers ago my buddy was having trouble with his heads/cam vette. It was running like ass. I noticed his exhaust was sooted up which made me first want to look at the O2's. We got a log and sure enough one of his O2's was flat lining. The car never threw a code for it. Might not be your trouble but would be worth finding someone to log the car for you to at least rule the O2's out.

edit:
another thought. How many miles are on your car and are you still on stock cats?

I'm not an expert, but I'll tell you as much as I do know. As for exhaust leaks, I hooked up a vacuum gauge, and that checked out, but not sure if that is what you're talking about. Don't know how to check the AIR pipes. I've got a fairly new paper filter on there, and changed the fuel filter recently also. I did take off the MAF when I put on the SLP lid, but I was very careful with it, and it looked very clean, so I didn't mess with it. I'm in Albuquerque right now, so I will see if someone can help me out with an autotap. You say that would be a good check for the O2's? I would definitely like to try and rule them out. I am at 60k miles, and am still on stock cats (and am not noticing any exhaust smells, either).

I appreciate the suggestions.