# Bypassing the O2 sensors?



## MEDEL514 (Nov 24, 2005)

I've been having an exhaust problem on my 2006 Nissan Frontier. I keep getting an erroneous P2A03 code on my truck which the dealer was telling me that its an O2 sensor. But I have changed all 4 of the O2 sensors since this code has came up and the problem has still came back, and I'm getting horrible gas mileage. I have an 06 and my warranty has run out, so I'm on my own on this one. 

Since I've replaced all 4 O2 sensors, I can rule those out as being the problem. Now the dealer says that it might be an exhaust leak that is causing the out of limits readings between the upper and power O2 sensors. I really don't want to drop $$$ into an entire new exhaust system, so I was wondering if there was something else that could be done. 

I remember hearing about people with 350Z's doing something to bypass the O2 sensors when they put on aftermarket exhausts. I guess it had something to do with the aftermarket CAT's or something. Could someone explain what it is that will bypass the O2's? I was gonna see if maybe that would work on my truck to solve the exhaust problem that I've been having since they are similar motors. Let me know if you guys have any insight, thanks!


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## SleepyS13 (Apr 10, 2009)

I did some searching around for you:

Found this, and this.

Do you think one of your Cat(s) (if you have 2) are shot? That may be triggering the error code, too.


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## Spongerider (Nov 18, 2002)

I think the by pass you're talking about is for the check engine light. You do need the the O2's when you're in close loop (idle) or you will never pass smog and still have bad gas mileage. 

Did you use OEM O2's? Also check to make sure they are working because I had a new O2 fail right out of the box.


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