Okay let me start out from the beginning the stealership charged me 3000 already and they dont know crap about the problem. basically they already replaced the o2 sensors and throttle body. I replaced test pipes with kinetix hfc to see if my service engine soon light would go away didnt help. i cleared all codes and that just made the car run like **** for 50 miles. i have codes
P1148
closed loop bank 1
P1278
air fuel sensor 1
heat bank 1
P1279
air fuel sensor 1
heat bank 1
P1276
air fuel sensor 1
heat bank 1
P0138
oxygen sensor
circuit high
voltage bank 1
sensor 2
P0158
oxygen sensor
circuit high
voltage bank 2
sensor 2

I am stumped. Im no professional but i have been working on car for 5+ years
all the o2 sensors were replaced, checked all plugs and wires and their tight and no bent pins. i just have no clue where to start or what to do to tackle this problem
If you can chime in on this with some information it'd be greatly appriciated.
Thanks,
Carl Penniman

 

Did you check the MAF?

 

Start from the actual beginning and tell us what the first problem was. Did you literally have all those codes pop at the same time?

 

Well the first problem was the ses light a click noise from rear axle and breaks squeaking. I fix the click noise and put new breaks and rotors on. Now for the ses light. I took it to a Nissan dealership. They said the o2 sensors were bad because of test pipes and the throttle body was shot so I had all 4 o2 sensors replaces and throttle body replaced. Then I ordered kinetic hfc online and installed those a week later and the ses light is still there. Took it back to Nissan dealership and they said the rear o2 sensors are unresponsive but how is that possible of they just replaced them two weeks ago. So yesterday I went to autozone and had the codes read and those were all the ones that come up. When I try to clear the codes the ses light goes away for fifteen miles but it goes from idling rough to smooth and misfires until after 20 or so miles it runs 100 percent perfect no rough idling no misfires no nothing but the ses light and a funky smell coming from the exhuastes but I think that's from the new hfc breaking in. Could this be related to a Maf sensor problem?!? Because I have a typhoon cai from previous owner installed. The filters kinda dirty I just hvent had time to get aroud to install a kn washable one because I want to get all the major problems fixed first

 

What would I be checking on the maf?

 

Leave the MAF alone. Something is affecting all those circuits, ground wire maybe, whatever it is you need to be able to understand electricity and read wiring diagrams.
If a sensor is unresponsive that means the ECU is getting no signal, we need to check that a signal is being generated and that the wiring harness is intact, then we move to possible ECM failure. Sensor, harness, ECM. Always, always check the basics first. Check the fuses with a fuse tester.

 

What he said ^

 

i already checked every puse panel. im good with elec. so reading diagrams is no problem for me. what if the ecu locks out the sensors and go off its premapped settings. because when i clear the codes the car runs like **** for 20 or 30 miles misfires and all. but after 20 or so miles is runs perfectly. no misfires, no powerloss, a little rough on idle but nothing to serious

 

ECM's do not lock out sensors. It may disregard the reading but there should still be something hitting the datastream. Clearing the code is resetting the fuel trim to base settings, if that is making it run worse than that is a useful thing to know to diagnose this.
Start free account at Autozone.com, they have alot of the FSM diagnostics for free on the webpage but you must register.

Find the diagram with the Air Fuel/Oxy Sensors and you will see they are on the same circuit. You will need a scan tool, DVOM, might be nice to have some good lengths of wire to run bypasses as needed. The HFC's could be the problem but they should not cause a sensor to not respond. Oxygen sensors are voltage producing devices, if no output then no power to sensor.

 

okay. i looked at the diagrams and can understand them and everything but this is getting to be a little to big of a project for me to tackle. i just dont have the time to work on this with work and all. yes it runs worse when codes are first cleared it misfires but after 20 or so miles it runs fine with the exception of a tad bit of rough idle. it's idling a little low for my likings around 600 rpm.

 

When did the MIL first come on? Did someone work on it? Check the grounds by the headlights. I can walk you through this if you want, it will be hard to find someone with the skills to diagnose and that is honest enough to not throw parts at it.

 

And did you check the fuses by the battery? I mean the ones you have to take the plastic under the windshield off to get to, and the IPDM thing near postive battery terminal.

 

i checked all the fuses including the one you have to take the plastic to get too and. no i didnt check the ipdm. would that cause something like this? and no noone worked on it. i bought it with the ses light on and have been trying to tackle it ever since. i though it was on because of the tets pipes but apparently i was wrong because i put hfc's on

 

That's a lot of codes! Good luck