I just threw 2 codes on my 2006 TRD/OR... (both were P0420). I've been running the DTLT Headers for several months with the O2 Simulators without any issues.
The conditions tonight were dry (no rain or puddles) and I'm trying to figure out why all of a sudden I threw 2 codes tonight?
Not sure if I should be worried, thought the O2 Simulator was supposed to keep me from throwing a code.
Also, when I installed the DTLT's I installed 2 new O2 sensors. They were the same make/model as new Toyota parts (Denso IIRC) and they might have 2k miles on them.
Anyone know why I'm having this issue? Maybe just need to fill up with 93 octane and no ethanol?