02 sensor help!!

PARTHAWAII

Test Drive
Location
Hilo
3.3 V6 with EGR and headers with cats together. I been having issues with 2 codes. My recent repairs were all 6 injectors and 2 new upstream 02 sensors deleted 2 downstream catalysts, Pacesetter headers direct fit with a flowmaster muffler. From inspection and not a bench test yet I dont see how both sensors remain at a high temp for so long causing the high voltage seen from the sensors. Please I need some guidance!!
 

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Muadeeb

Nissan al Gaib
Admin
Location
Dallas
Looks to me like a fuel system issue. The 02 sensors are complaining that the exhaust is too rich (or the sensors are bad). Start with diagnosing the Evap leak. I'm not good with those, so maybe @Prime can help with that, or another member. Once that's clear, we can tackle the O2 sensors.
 

PARTHAWAII

Test Drive
Location
Hilo
This will be the 3rd time chasing the leak. On the fuel system I've changed my filter and all 6 injectors with seals including the flat one. Hard part is my headers wont work with any 02 sensor. It has to be a NTK shorter length than the Denso. They are not carbonated up in anyway. I guess I'll have to look at my fuel pressure with a gauge and maybe reseal all injectors. See if I need a regulator. If the pump is going bad I'll see it below the 30-35psi spec. I just changed those sensors too.
 

PARTHAWAII

Test Drive
Location
Hilo
Did you have to extend the wires for the
No. The headers are direct fit. Just the angle the bung is welded puts it close to the steering shaft. So the sensors are to fit stock positions regardless of the angle. However the denso sensors I've bought. The harness is the same length some how on both sides. Must have orderd the wrong sensor from the parts store I always go to.
 

PARTHAWAII

Test Drive
Location
Hilo
No. The headers are direct fit. Just the angle the bung is welded puts it close to the steering shaft. So the sensors are to fit stock positions regardless of the angle. However the denso sensors I've bought. The harness is the same length some how on both sides. Must have orderd the wrong sensor from the parts store I always go to.
I'm talking about the physical length of the oxygen sensor itself.
 

PARTHAWAII

Test Drive
Location
Hilo
Looks to me like a fuel system issue. The 02 sensors are complaining that the exhaust is too rich (or the sensors are bad). Start with diagnosing the Evap leak. I'm not good with those, so maybe @Prime can help with that, or another member. Once that's clear, we can tackle the O2 sensors.
Fixed the evap. About 60% of the hoses under the vehicle have been found with broken clips and cracked hoses. I just got my new sensors in. My family and I been using my truck back and forth around the island and put down about 1200miles road tripping it around. What would be my next area If the high voltage signals come back? Fuel filter is already done.
 

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PARTHAWAII

Test Drive
Location
Hilo
Looks to me like a fuel system issue. The 02 sensors are complaining that the exhaust is too rich (or the sensors are bad). Start with diagnosing the Evap leak. I'm not good with those, so maybe @Prime can help with that, or another member. Once that's clear, we can tackle the O2 sensors.
I'm at the end of my rope. What part of the fuel system should I start with?
Fuel filter and injectors are brand new. Should I add like a regulator?
 

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Muadeeb

Nissan al Gaib
Admin
Location
Dallas
Check your grounds; there are two at the top of the intake. There should also be one from the body to each exhaust. Beyond that, make sure you didn't wire the sensors backwards.
O2%20Sensors.jpg
 

PARTHAWAII

Test Drive
Location
Hilo
Check your grounds; there are two at the top of the intake. There should also be one from the body to each exhaust. Beyond that, make sure you didn't wire the sensors backwards.
O2%20Sensors.jpg
So far the headers to exhaust I've cleaned both sides and I've found only 1 ground from the harness to the intake and I've had it loose. Cleaned and tightened. I'll clear the codes tomorrow and come back if the codes come back again.
 

PARTHAWAII

Test Drive
Location
Hilo
Fixed! After going through all body grounds getting my facelift frontier ready for a roadtrip and a trip to the body shop so far it's not running rich as it use to. Thank you for your help everyone!
 
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