I have a 99 silverado 4.8L. I found some o2 sims at thunderracing.com, but I noticed the models started at 2000 and said 5.3L only. Is there a difference there? If so, anybody know where I can get the right ones for my truck. I really want to get a little more sound out of my current setup. Soon enough I'll have the headers/electric cutouts on, but for now, I need a little cheap sound upgrade. Thanks

 

they should be the same... don't take my word for it though... gl

 

if you can get access to ls1edit, or someone who tunes.. they can turn off the rear o2 sensors.

 

You need to be observant of the "KEY" inside of the 02Simm connector. There are two different style keys. You can disconnect one of yours on the factory O2 connector and tell Paul or Angie at Thunder how the key is configured so you get the correct connectors on your O2Simms.