Hey guys,

Ive had my evo since last july when i sold my wrx and now I'm ready to start working on it. It had a mbc and licp when i got it and I just copied my rom and am going to send it to jestr tunnning this week. I'm guna go with just the tbe and a tune and I want to know a couple of things before I jump in.

Just wondering how many o2 sensors are after the turbo? I think when I go tbe I'll just take them out and plug the bungs in the exhaust and tune out the cel, this way I save my o2 sensors. In my wrx I ran catless and burnt an o2 sensor and I don't want to do that again. This guna work?

Also is the tbe for an 8 mr different from a normal 8 exhaust?

Thanks for any advice or help

Kurt

 

hey whats up. i work for subi currently and can tell you they burn out o2's regardless of stock or modded. you shouldn't need to pull out any o2's as 1 is after the turbo before the cat and 1 is after the cat as a monitor. your still running off the stock ecu correct?

 

yeah its the stock ecu, I haven't put any exhaust on yet though, i wanted to get this all straight first

 

from what i remember if you unplug your 02's your car will always run in open loop due to no sensor feedback, causing over rich condition and poor low/mid throttle driveability. i would just leave them in and put a fouler or some other type of siganl tricker on the secondary for the cat if you install a test pipe. others can chime in if you can tune the stock ecu for what your looking to do, but i don't believe you can.

 

cool, thanks man. And i just read that the mr exhaust isn't any different than a normal one, so thanks

 

look up tephra mod. thats basicly what u need. you can program in a o2 heater simulator and o2 sensor simulator both for the rear o2 sensor. i took out my rear o2 sensor. i have my wideband in that bung

 

You need to leave the front O2 alone (The one in the o2 housing), as that one is part of the closed loop mechanism that controls fuel/emissions for idle and cruise. The rear o2 is in the catback section and you can either remove it with a ECU hack or do a mechanical fix (spark plug antifouler trick) to keep from getting codes. I dont know how you 'burnt' an o2 sensor in your wrx but the only thing that will happen if you dont do anything is you'll get a CEL for cat inefficiency in a Evo if you don't have a cat. This doesnt affect anything except turning on a light on your dashboard and of course failing emissions testing. Most people use a mechanical fix because it's easy, cheap, and it works.

 

yeah, I wasn't guna move the first one, I should have said that, I just don't want a cel or to lose a o2 sensor. thanks