Ok, so I kept getting a CEL after my TBE install (catless). Yes I installed the 2 non-foulers! I got a CEL so I did the batt reset clear 2 times, but it kept coming back after 50 miles or so. So I went to auto Zone and pulled the code today. Only code was P0137 "EGO Sensor Circuit Low Voltage (Bank 1 Sensor 2)"

I did some searching, and EVERY post I found with this code was someone using a Perrin O2 sim? That would lead me to beleive that this is a wiring problem with their Perrin O2 sims? In most cases that seemed to be the case. But as I stated, im using the non-foulers, so my ONLY wiring problem would be in the stock o2. This "low voltage" code has to be the wiring right?

I did have a hell of a time getting the o2 sensor out when I installed my TBE, and might have (no way to be sure ) twisted the wires enhuf to pull something loose in the o2??? My question is should I buy a new o2 sensor? Does this code mean that a wire is loose/shorted out in there? Or should I have a different plan of action? I did clear the code with the OBD II tool I used at Auto Zone before I left, and the light didnt come back on the way home. I will need to put more miles on it to see if it returns though. Im assuming it will though. Thanks guys.

 

yes, it'll need more miles to verify that it doesn't come back on. It's not an immediate thing. With the two foulers, your wires should be really close to the underbody of the car, and it's possible as you hit bumps and the exhaust moves a bit, you pinched the wires against the underbody and damaged them. I'd crawl up under the car and verify the insulation isn't broke on any of the wires first.

 

I have access to a lift and I was under there the other day to tighten the bolts after everything had settled, and checked the wires realy good. There were no rub marks on them. I also have quite a bit of clearance between the car and the non-foulers too. My only concern is that when I removed the sensor from the stock cat I may have twisted the wires too much.

What code do people normaly throw if they dont run any non-foulers? Im guessing it isnt the same as the one im getting. I did a search for my exact code, and got less than 1 page of matches. I was expecting to find out that my code was for too much flow or something. Its seems weird to have been for low voltage??? The non-fouler was drilled in a press with a BRAND NEW bit that went through like a hot knife through butter. Im very confident that the non-foulers are as perfect as you could get! So I know its not those. I realy think I may need a new sensor.

Anyone ever fix/clear this code without getting a new sensor??? Ill keep you guys posted on what happens, just incase it will help anyone else down the road.

 

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I couldn't get anti-foulers to work. I kept thowing the code. This is on an 03 Evo. I eventually put on the Perrin simulator and problem solved. I never checked the code though, just know the check engine light came on after the test pipe install, cleared it several times and it always came back with the anti-foulers.

 

Ok guys, I put a few more miles on it to and from work today (15miles or so) and still no light. My new line of thinking is that the P0137 "MUST BE" rest by an OBD II scan tool. The last time I tried the batt reset trick it came back on in less than 2 miles. Thats why I pulled the code. Ill keep putting miles on it and keep everyone posted.

I actualy put on the 2 non-foulers "the first time" drilled with a drill bit that had steps on it. 1 size then it steps up to the next size, and so on. I dont know what that type of bit is called, but the shop didnt have a 1/2in drill bit. Thats when I got the first CEL. I figured thats what caused the code, so I bought 2 more non-foulers and a NEW 1/2in drill bit, then installed it correcty. Im thinking that first code may have been stuck in the memory even after the batt reset. Hopfuly the OBD II scan tool reset has fixed it for good. Only time will tell though.

 

bad o2 sensor?

 

im having a similar problem, from what i read in other threads there is acutally a patch for ECU flash to solve the problem.

 

Realy? I did alot of searching and never read that? Would you mind posting a link to that here for me? Thanks!

 

FYI, its called a step bit or a unibit. Also, I have the perrin o2 stim, and it worked fine, but I dont think this was an o2 sensor issue. The only thing I would think it was wires that got melted and shorted. When me and a friend put a downpipe on his subaru, the wires hung to close to the downpipe and it ended up melting through the wire insulation and shorting the o2 sensor.

 

For reference, from the manual:

DTC P0137: HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE (SENSOR 2)

CIRCUIT OPERATION
• A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal No. 75)
from the output terminal (terminal No. 1) of the heated oxygen sensor (rear).
• Terminal No. 2 of the heated oxygen sensor (rear) is grounded with ECM (terminal No. 92).
.
TECHNICAL DESCRIPTION
• The output signal of the heated oxygen sensor (front) is compensated by the output signal of the
heated oxygen sensor (rear).
• The ECM checks for an open circuit in the heated oxygen sensor (rear) output line.
.
DTC SET CONDITIONS
Check Conditions
• 3 minutes or more have passed since the starting sequence was completed.
• Heated oxygen sensor (rear) signal voltage has continued to be 0.15 volt or lower.
• Engine coolant temperature is higher than 76°C (169°F).
• Engine speed is higher than 1,200 r/min.
• Volumetric efficiency is higher than 25 percent.
• Volume airflow sensor output frequency is 56 Hz or more.
• At least 20 seconds have passed since fuel shut off control was canceled.
• The heated oxygen sensor (front) outputs 0.5 volt or more.
• After the ignition switch is turned ON, the changes in the output voltage of the heated oxygen
sensor (rear) is lower than 0.078 volt.
• Monitoring time: 10 seconds.

Judgement Criteria
• Making the air/fuel ratio 15 percent richer for 10 seconds does not result in raising the heated oxygen
sensor (rear) output voltage beyond 0.15 volt.
• The ECM monitors for this condition once during the drive cycle.

 

Im sure this all very useful information, but im not realy sure what to make of it? Just a little confused i think? Do you think you could explain this too me a little please? Is it saying what the problem might be, or telling me to do/check anything in particular? Sorry I cant seem to understand what it is your trying to show me exactly.

I did drive it all day today as well with NO CEL yet!

 

im having the same problem. except mine is p0138 "EGO Sensor Circuit High Voltage (Bank 1 Sensor 2)" still running stock cat.....the cel light was on for 3 weeks straight then today just went out. i hooked the scanner up to it and cleared the code and on the third start up it came back on...drove it for and hour or two and it went out. everytime it goes out and i clear the history code, always on the third startup it comes back on

 

48 miles! Thats how many I made it after I cleared the code. This is just getting anoying!!! Im going to pull the code to be sure its the same one. Stay tuned.....

 

did you use the long sparkplug anti fouler or the short ones? i had to use two long anti foulers