Thread: o2 Sensor Question

so i dynoed my car and made some shitty power, i check for codes and im throwing an 02 sensor code. now i want to make sure i go get the correct one. when i bought my sensor i was givin Bosch P/N 13039, threw a small search i found it would be better to use the 4 wire15727 because of the grounding ability and the other sensor had some grounding issue(13039)... can somebody please confirm what sensor i need to get its for an OBDII set up(if that makes a difference)....

edit* im looking for the 1st 02 sensor

http://www.sr20-forum.com/audio-electronics/4595-regrounding-o2-sensor.html
still reading^^^


thank you and im still searching...

i really dont think an o2 sensor has anything to do with low power reads bro. they are more for idle and cruise.

just curious what kinda power did you get an whats your setup?

not much more than my DE made and far from stock, when I fix the problem/find out whats wrong ill post up on the info...

ok well double check your solenoids to make sure they are coming on when they are suppose to and staying on.

with out really knowing the setup or whats happening on the dyno i cant offer much more help lol.

good luck hope ya figure it out.

O2 sensor is not used above a certain RPM/Engine Load point. Thus if you just reset your ECU, and did a run the O2 sensor being bad shouldn't cause poor numbers.

There are two exceptions that I can think of though:
1. Faulty front O2 sensor causes the ECU to go into half limp mode, where it sprays the injectors twice in every cycle.

2. Long Term Fuel Trims... You start with an A/F base of 100, your O2 sensor sniffs the narrow-band and ships that information to the ECU, ECU then compares it to the base map. Your A/F base gets adjusted up or down, if I recall correctly anything below 100 is mixture leaner then O2 sensor sniffs, anything above is richer. This adjusts your AFR's across the board, now I am not 100% sure if this touches the base AFR's when narrow-band O2 sensor is not used (above certain load/rpm).

So what does this mean? If your O2 sensor thinks you are richer then you really are, which a poor ground will do that, then it might lean out/richen out your map and cause worse numbers. Dyno wideband would tell you that though.

When I installed the 4 wire O2 sensor (onto the SSAC header) my gas mileage went from 27mpg to 33 mpg (which it was before on an OEM header). I didn't have a wideband at the time, but that tells me a poor ground made the car richer.

ok so the car is Cammed with N1s and other supporting Mods and only made 174whp, im in the process of doing a tune up to correct one area at a time, and go from there.

the car does have a wideband, lets say i pound 1st-2nd the car does run rich, but enough for me to loose so much whp? my funds are low so it will take a little time to correct this...

i think a tune up is a good idea, i should have done one before i dyno'd last because i only got 180whp sae after tuning an thats with n1's, ssac, 3" exhaust an wai, i recently found my cap an rotor in dire need of replacement. i really should have done it before dynoing because i think thats why i had to pull so much timing to gain any power.. i was getting around 174whp before i pulled a bunch of timing to finally settle at 180.

with those numbers i can bet your cams are indeed coming on cause if not i really dont think you would of seen that much power.

what are your afrs when you do a 3rd gear roll from like 4000?

ill let you know tomorrow , i have the dyno sheet but it does not say rpm just speed/whp and all on top that its with a sr16 box(plus one pull was done in fourth and i dont know what sheet i recieved), so numbers may be a little different than you if your using a standard box. i just checked gregs web site $87 is my magic number for cap rotor and wires...

what kind of dyno was it? an are the numbers sae?

and yea im going to be giving greg a call soon my self.

Numbers are STD o the dyno. Jimmy what bin you have on your ecu? Also ecu?