I have been trying to figure out my weird problem where the car runs perfect in open loop mode but when I program the car to run as stock in closed loop it runs like crap. I made a previous post about this and how I bought brand new GM 02 sensors blah blah blah. Well I have had problems with my rear 02 simms before and now im wondering if they might be a possible problem again. After being under my hood messing with other stuff for the first time ever I noticed a red blinking light on my passenger side 02 simm?!?!?! I didnt know these had lights on them. Anyway does anyone know what this means and why?
Thanks

 

it is an indicator light to show you they are working. I used to have them. Now I have a 95 ecu which was custom tuned by MADWOLF to delete the rear 02 sensors. I HATED dealing with the rear 02 sensors.

By the way, do yourself a favor and make SURE you have the sims plugged in to the REAR 02 sensors. I let a buddy plug mine in while I installed my old headers and failed to notice for 5k miles that he plugged the sim into one of the front 02 sensors!! can you say SUPER RICH??

 

How is that even possible to attach them to the front two sensors when they are completely different connectors? the 02 sims should be a square 4 pin connector and the fronts should be a flat 4 pin connector. No possible way to get them swapped. Can anyone else confirm the red blinking light is to show they are working and functioning properly?

 

woops, I meant he left one unplugged. Sorry. You were right. The light does mean they are working though.

 

I have the Casper Electronics SIMM's and they have the blinking LED which is an indication of operation but not necessarily proper operation. However I don't think even if you had a rear O2 problem that it would cause the problem you are having. Do you have any way of logging some data or even getting some wide band info from a chassis dyno? That might help with the diagnosis. Good Luck.