So I installed a little cheapo 02 sensor, its called an ARM1, 4-wire heated, uses different color LED's to indicate AF.
The only time it _ever_ gets near lean is in drive, at idle (900rpm with both the oil and water at 180* or higher). Touch the gas, with the brake on, and it poof, 1000rpm and its at the last green/first blue, which is like 12:1 or worse according to the companies conversion chart.
Cruising is either 1st blue (11.5:1 or worse) or last green/1st blue.
Dipping into the gas 3/4 throttle it doesn't even flinch.
I am taking what will probably be my last trip to the track this year on saturday.
I was just wondering, and I have not done a WOT test or a hard-hooking test to see where my AF goes, but assuming I run pig rich-- is this costing me alot, or just costing me gas flying out the tailpipe and a set of burnt eyes and stinky clothes?

Just wondering.. I won't have time to tweak the car between now and then, I posted about this earlier but had to leave on an emergency trip and never got to follow up with questions, now all I can do is wash the car and load it onto the trailer, and hope my new converter and 16 hour (yes... laugh all you want) install was worth it, or worth something...

Matt

Well for now I would not assume or change anything until you have done more testing. I don't know your unit. However I have a friend that has a sensor with lights. We compared it to my Innovate Tech wideband 02. His unit turned "red" at about 14.5 to 15.0. (it was not consistent) It was yellow from 14.5 down to around 12.5 to 12.0. It turned green below 12.5 to 12.0. I have found that in my combo, I idle around 11.0. At WOT it is right at 12.5 where my car makes the most power. As far as off the line launch goes. Most of the cars I have worked with spike lean at WOT then go rich as the accelerator pumps come in. They then level out to about where they are going to be. It is usually around a second until the afr stabilizes. Now all the cars I have worked with have Holleys on them. Most of them have reacted about the same with an off the line launch. I had one exception to that. So for now I would check it out at the track and see what type of results you get. Most of the dyno guys I have talked with have said most cars make the most power somewhere between 12.8 and 13.2. In my case however 12.5 is the magic number. Monte

I also have the LM-1. Even with a cam with big overlap, my idle is at 14.5-14.9 and the exhaust has no odor to it. I'm impressed.

Anyway, you don't lose much power when you go too rich. If you go too lean, then you really start to lose power. Currently, you only will suffer from fouled plugs (possibly) and poor miliage, that's it.

It's kinda like being at idle. A rich idle will still be fairly smooth, while a lean idle will be rough.