[Burs]

Hey guys, just wanted to drop by and introduce myself.

This is a poor quality cell phone picture of my (mostly stock) 03 Nissan Sentra SE-R Spec-V. Picked it up at a used car lot recently. Car's real clean and in good shape. 152k miles on it, but it runs nice. The interior is mint, and the exterior is pretty good as well. Only issue is an idle search from 1-2k which, as I understand, is something to do with the IAC valve.

I look forward to learning and becoming a part of the community! Let me know if any of you are in SW PA. Maybe we'll set up a meet.

-Burs

 

[i68k]

welcome aboard!

first you should read the precat and butterfly faq in the tech section:
http://www.b15sentra.net/forums/showthread.php?t=135241

did you pull an ses code for your iacv? did you try doing the 3 relearns in the fsm? the fsm is free download around here somewhere.

 

[Burs]

My car's already got a Hotshot header on it, so I think I'm good on the precat thing. As for the butterflies, thanks, I'll check that out. And no, I haven't done the pedal dance yet, I'm going to try it as soon as I find my stopwatch.

EDIT: Yeah, I pulled an SES code for IACV flow higher than detected or something of that nature. Also for the 2nd O2 sensor.. Whoever had the car before me was a member of a B15 forum and he claimed he already took care of these issues. No harm in checking though, and so I will. Also, if it helps, I have a Nismo CAI on the car and a Hitachi throttle body.

 

[i68k]

maybe you got a p0507 - idle higher than expected. try doing ALL 3 relearns in order, before you start throwing parts at it. the iacv isnt cheaper esp when its recommended to get a genuine nissan for this part (both maf & tb should be genuine nissan).

your nismo cai is ok, also long as theirs no cracks or leaks. you could have a vacuum leak cause and idle bump, which could lead to a loss if idle or idle bounce 1k-2k. i believe hitachi makes the genuine nissan oem tb.

EDIT- as for the second o2 sensor, if you have a header, and your ses doent have a p0420 cat code, you should be good. most likely there's like 'spacers' on the lower o2, sometimes people sim/rewire them as well. hotshot is a good header

 

[Burs]

maybe you got a p0507 - idle higher than expected. try doing ALL 3 relearns in order, before you start throwing parts at it. the iacv isnt cheaper esp when its recommended to get a genuine nissan for this part (both maf & tb should be genuine nissan).

your nismo cai is ok, also long as theirs no cracks or leaks. you could have a vacuum leak cause and idle bump, which could lead to a loss if idle or idle bounce 1k-2k. i believe hitachi makes the genuine nissan oem tb.

EDIT- as for the second o2 sensor, if you have a header, and your ses doent have a p0420 cat code, you should be good. most likely there's like 'spacers' on the lower o2, sometimes people sim/rewire them as well. hotshot is a good header

I'm pulling a p0420, actually... I believe its affecting my mileage so I'd like to deal with it. And the CAI is like new, no leaks anywhere that we could find. All the vac lines look to be in good condition as well.

 

[i68k]

p0420 is your cat code, and is directly affected by the o2 sensors. either one could be bad, assuming theyre good, you should have some anti-foulers on the lower o2 (closest to the ground or muffler). you need to make sure both are not leaking as well. essentially, where your hotshot header is, there is normally an oem cat, but the hotshot removes that precat. the o2 sensors collectively read the efficiency of the precat. so, you have to trick the lower o2 to read a lighter value than the primary o2 (top of header, away from ground). this is done usually with anti-foulers, which move the lower o2 sensor away from the exhaust stream, to read cleaner air if you will.

as for your gas mileage, with the p0420, your ecu will normally attempt to richen the afr, causing a lower mpg. in your case, possibly other problems causing the afr to richen as well.

EDIT: did the realearns work, dont forget to do ALL 3, in order after youve fixed your lower o2 sensor.
1-accel pedal released learning
2-throttle plate closed learning
3-idle air volume learning

 

[Burs]

p0420 is your cat code, and is directly affected by the o2 sensors. either one could be bad, assuming theyre good, you should have some anti-foulers on the lower o2 (closest to the ground or muffler). you need to make sure both are not leaking as well. essentially, where your hotshot header is, there is normally an oem cat, but the hotshot removes that precat. the o2 sensors collectively read the efficiency of the precat. so, you have to trick the lower o2 to read a lighter value than the primary o2 (top of header, away from ground). this is done usually with anti-foulers, which move the lower o2 sensor away from the exhaust stream, to read cleaner air if you will.

as for your gas mileage, with the p0420, your ecu will normally attempt to richen the afr, causing a lower mpg. in your case, possibly other problems causing the afr to richen as well.

EDIT: did the realearns work, dont forget to do ALL 3, in order after youve fixed your lower o2 sensor.
1-accel pedal released learning
2-throttle plate closed learning
3-idle air volume learning

The O2 sensors are both new. Got a part number for that anti-fouler, please? Also if you could link me to "all 3" relearns, I'd appreciate it. Thanks.

 

[i68k]

you should be able to use the 'search' in the menubar, or search from google or something.

all 3 relearns are in the fsm (Factory Service Manual) you can download them here:
nicoclub.com/fsm
allsentra.com/fsm
here's a reference:
http://www.b15u.com/sentra-specific...learn-throttle-body-relearn-idle-relearn.html

what you will be looking for is called a "spark plug anti-fouler". you will need to make sure it will thread onto your o2 sensor. you will need a 2pack, one will have to be partially drilled to fit onto the o2 sensor, probably a good idea to goto an auto parts store. make sure you put the antifoulers on the lower o2 sensor, NOT THE o2 NEAR THE HOOD! here's a ref i think has part#s:
http://www.b15u.com/sentra-specific...oulers-remove-ses-light-o2-sensor-spacer.html