So you're contemplating catless headers for your off-road vehicle but want to get rid of that pesky CEL and get your car in an emissions ready state . Well as of now there's 4 options:
1) Spacers/Defoulers (
Fabspeed)
2) O2 Simulators (
VRSF)
3) DME Tuning (
AA or
BPC)
4)
Relocate rear o2's
Couple things to note
1) Spacers/Defoulers can be hit or miss but Fabspeed just released a new o2 spacer with mini catalytic converter. This 2 piece design with angled fittings also allows for an easier install when clearance is limited.
2) The newest line of sims by A r e a 74 has built in software that reads the actual o2 sensor voltage and cleans it up so the PCM thinks a functioning cat is present.
3) Tuning is the easiest but most costly. However some n52 owners reported that over time their tune was no longer able to get the oxygen monitor set as complete despite having done so before.
4) M owners have been able to relocate rear o2's by using euro cats but no such thing exists for n52's. Presumably you could install a pair universal 200 cell high flow cats.
What I Chose
I chose to go with the o2 simulators due to ease of install and the cost being similar to Fabspeed spacers. The downside is if your rear o2 connectors aren't easily accessible (e.g. underneath car), it may require you to install them by the DME. In order to minimize splicing, I used
Posi-taps and Posi-locks.
I will update this thread in the next few days to see how they hold up.