Help...LS1 Vette throwing O2 code

My dad's '99 Vette had an SES light go off, so we went to Advanced Auto to get the code read. It came up right rear O2 sensor and right rear O2 heater core...or something like that. The only problem is he has an X-pipe after the manifolds that he installed when he did the !CATS mod...which means, he's running O2 sims. So, how could he or why is he getting these codes???

We had Advanced Auto delete the codes and they haven't come back yet. It just seems odd to get a code like that when he's running O2 sims. :confused:

O2 sims are notorious for being unreliable. If the code comes back try swapping o2 sims to see if the problem moves, if it does, then try a new sim. Thats all I can think of, Good Luck

I just got done replacing an O2 sim that was 3.5 months old :mad:

The thing that gets me is the car is a 99 and only has 4900 miles on it. So, the simulators probably only have 2K on 'em (if that). It's nice that Thunder Racing sells them individually since we only needed 1.

:irk: