Current mods:

OBX-R headers w/ O2 sim
NWP spacers
Block off plate
Tsundo 2.5" catback
17* Adv timing
I ONLY RUN PREMIUM

Now I have codes

P0138
P0158
P0420

What should I do?? I suspect that my cat is clogged or close is that my prob??

If i straight pipe? Gut the cat? what would it sound like?? I have all aftermarket exhaust except my axle back is stock.

 

So no one has any suggestions??

 

I would suspect the PreCat is the problem, a bit surprised to see the two O2 rear sensor code considering they are simulated ... however the P0420 is pointing to a problem with the Precat Catalyst system below threshold. You could go with a test pipe in place of the PreCat but I believe it will be very loud

 

In reading about your current issue, some have suggested spark plug replacement (when were yours last changed?) as well as adding a fuel injector cleaner on your next full tank fill up to clean up any gumming up of the injectors ... just a couple of other idea's to help

 

P0138 - Heated Oxygen Sensor 2 Circuit High Voltage (Bank 1).
P0158 - Heated Oxygen Sensor 2 Circuit High Voltage (Bank 2)
P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
Your first two codes are heater codes which the simulator you say you have installed doesnt simulate so you need to wire a resistor into each one of your heater wires from the secondary o2's. The PO420 could be do to a bad primary o2 sensor or could be that your simulator is wired wrong

 

Just gut the cat or straight pipe it. I don't think it will sound bad as you have a factory muffler.

 

just replaced plug about 5k ago

 

This is such horrible advice. Don't add a fuel injector cleaner to your gas tank. read these forums everyone has had bad experience doing them. I put a bottle of techron into my old honda civic and it started knocking for 3 weeks.

 

hopefully you get the issue fixed man, lemme ask... sensor 2 is secondaries right???

 

P0138 - Heated Oxygen Sensor 2 Circuit High Voltage (Bank 1).
P0158 - Heated Oxygen Sensor 2 Circuit High Voltage (Bank 2)
P0420 - Catalyst System Efficiency Below Threshold (Bank 1)

 

soooooooooooooooooooooooooooooo they are the secondaries right???... nvmd i got the answer... i've got a question also... wouldnt the reason for the P0420 code be because of the P0138 and the o2 isnt detecting the cat??? so fixing P0138 takes care of P0420??? just curious...

 

i would say yes

 

knowledge lol

 

IGHT so what is the fix replacement?? or space the O2?? and which ones are simulated by my 02 sim??

 

should be both secondaries... u fix those, could be ya o2 sim gone bad idk... but you fix the two primaries and my guess is that it will most likely take care of the cat code...