If your lifters were bad, you'd be hearing it. Me, I'd drive the car and keep a watchful (listenful?) ear on it.
Fyi, your LS1 engine is nothing like the LT1 you had in the 94, they're a totally different animal. Also, the owners manual recommends using 91 octane gas. It will run on 87, but via the knock sensor in the block, the computer will retard the timing at the slightest knock (before you can hear anything), and engine performance can diminish. If your engine has carbon deposits on top of the pistons, or on the heads, or if you get crappy gas, the timing that gets pulled by the computer might not be enough, and the engine will make a ping/knock sound. This noise would happen when the engine is under a load (accelerating), not at idle. With 87 octane, you're teetering on a fine line, see how she does with 91 octane, or put 93 in just this time to overpower the 87.

 

I cannot begin to tell you how upset I am that I have been using the wrong octane gas. I stopped using the higher octane after the first oil change. My owners manual does not specify what level to use, by the way. I just looked at it again and there is lots of stuff about additives and other useless information about California and other things but ZERO about the type of gas to use.
I think I am going to keep an eye (ear) on it for a bit.
Thanks again for your advice. I can't tell you how much I and my beloved Camaro, appreciate it.
deb

 

You're welcome. Pay your owners manual another visit and go to section 6-3.
Here is the pdf version: Gas octane is on page 249 of the doc: http://www.chevy-camaro.com/faq/cama...2002camaro.pdf

 

I went to 6-6 today because the index said that was the page about fuel. Ohhh, I cannot believe after all of these years of thinking I was doing the right thing, I missed that.
However, it says "use middle grade or regular unleaded gasoline rated at
87 octane or higher, but your vehicle’s acceleration may
be slightly reduced. " I use only use Mobil and it's not less than 87. And I have never had reduced acceleration. I have often commented to people that the car's ability to respond so quickly and avoid an accident, has saved my life 100's of times with these terrible, uninsured, unlicensed drivers that have overrun South Florida.
As soon as I can get that tank down to half, I'm rushing to the premium pumps.
How upsetting. I feel like I have betrayed my best friend.

 

It is not a big deal, you did not hurt your engine. GM used the 91 octane to hit its MPG and HP ratings so it had to list it as the fuel required. As told to me by a GM engineer "We are not going to warranty a car that could be damaged by someone putting the wrong gas in it." You would be amazed at what is sold as 91 octane in some of the tourist traps around the country.

As Camaro 69 said you have what is called a knock sensor that protects the engine. This does reduce the power but I doubt you are driving the car in a ways you could tell. Let say you drag raced you car at the track. with 91 octane you may run a 13.0 in the quarter mile. If the knock sensor sees pinging from lower octane gas in may retard the timing 2-3 degs so now you run a 13.08. If it was really bad gas you could see a 13.25. A bracket racer that races every weekend would feel a 1/4 of a second at 0-100 MPH but I seriously doubt a none racer could tell the difference.

At the beginning of this thread I told you my car had a lifter tap for the first 3-5 minutes first thing every morning. It has had that since I bought it last year. Last weekend I did my third Mobil one oil and filter change. It has not tapped since. it has a very light, I will call it a lifter rattle when I first start it but I have to get pretty close to the hood to even make it out. It is only slightly louder then the injectors. When I first got the LS1 another member had recommended a rocker upgrade just because the issue is so common.

If the engine is not making noise and you have good oil pressure. Drive it. If you end up really needing a rebuild it is almost always cheaper to buy a remanufactured engine then it is to fix a stock high miles engine. So it really does not matter if you drive it and find out you hurt it. Get a triple A car and don't worry about it. The only case you would be hurting something that could be repaired would be if you loose oil pressure. If that happened you should get a check gage light flashing on and the oil pressure gage would read zero. Then if you get the car shut down fast enough it could be repaired. Pretty much any other internal damage would not be worth the cost of a rebuild.

 

I am sure you are right. It's unlikely I'd be able to tell the difference in terms of acceleration speed. But I do feel that since I've been driving this car for 14 years, I can tell when something is not right. You know what I mean? I only took it to the dealer last week because the battery gauge was in the low range and by the time I drove the 2 miles there, the battery gauge was normal again (the car had sat for 12 days without starting because I was out of town on a business trip). When the knock started in the engine while he was telling me nothing was wrong with my alternator belt or battery cables, I caved in and let them look at it.
It has not knocked since the oil change on that day.
I'm going to continue to drive it and keep my ears open to any changes. I've often thought I'd get a rebuilt engine if the engine ever (okay, okay, I know it will happen ONE day) goes. But I really HAVE taken care of it, religiously, so it pains me to think I missed something so frigging basic as the octane level of the gas.
But thank you so much for your comments!
deb

 

i am still wondering what the codes are about. rich on both sides and it comes and goes.

 

172 is left side rich, 175 is right side. One common thread for both could be due to a dirty or faulty MAF sensor. I would first have the sensor cleaned and see what happens, since that's a cheap and inexpensive possible fix.

 

Yes, I wonder about it too and my biggest challenge is finding an auto repair shop to take the action suggested--to start with the least expensive cause, the MAF sensor. I found a speed shop that's highly recommended but I don't see them wanting to start with something that I would ask them to do.
What I won't do is what I used to do--just take in the car and say the SES engine light is on and what does it mean. In the past few years, I go in with the code and this time what I'd like to do is ask they clean it first. But I expect push back. No matter who I take it to.

 

I would run 93 from now on an see if you don't hear that at knock at all ,like said we are lucky if 93 is 93 octane .like 92.5 ,91 would be like 90.5 an 87 like 86.5 ,my guess is a good chemist could have the local gas station checked for octane rateing if you go to the same place .but I have never had any problem with running 93 in everything I own 4 stroke 2 stroke that has an engine ,has a better shelf too seems ,like my base 3800 I run 87 but run 93 a few times a year ,my old lawn mower of 10 years old B&S 4hp has ran on 93 all that time same plug only cleaned once, seafoam a few times a year is good to for oil crank case an gas system about 4 ounces each