Disconnected O2, new premuffler!!
 

I can't believe the difference!! It all started when I bought a used SS premuffler from a fellow board member, shortly after that I bought a complete exhaust system off ebay for $65, in excellent condition, with the intent of reselling to fund the premuff install. Turns out my whole system was pretty much shot so the whole thing got installed. Decided to leave the O2 sensor disconnected to see if everyting I've read was true. The reuslts:
1. Butt dyno agrees with the 20hp estimates!
2. All idle issues (many and varied) have vanished!
3. The difference in throttle response is amazing!
4. High PRM pinging gone!
5. Really great exhaust sound
6. Heat in the cabin!! (my exchagers were really bad)
7. Total Parts/Labor =$635!!!:D

Just about set for my trip to the Redwoods!!
Thanks to all for the information that led to this truly amazing transformation!!

Now that you have the O2 sensor removed, you may want to richen your mixture and set your max timing advance to get even more performance. The O2 sensor could have been leaning out the mixture too much and may have contributed to the detonation, especially if you were already a bit lean. For reference, a lot of us with no O2 sensor run at 35 degrees max advance at 6K RPM's and 3.5% CO fuel mixture.

Hope your day in Oregon is as nice as SoCal today :) Get that top down and go for a drive!!

-B

Thanks Brad. Mixture was richened but will call to make sure he set it right. The weather wasn't that great but did get a good 100 mile run in. My driving experience is so much different now I'm dreaming up errands just so I can drive it!

My mechanic has set the mixture at 2% and says he will reset it to 3.5% but thinks that is way too rich. I trust the experience fo this board more than him but would appreciate some info I can give him os he doesn't think I'm an idiot (don't want him to know :) ). thanks for your help!