Got More Boost After Changing 02 Sensor.

[Fletch]

I changed my 02 sensor in my r33 and my boost is up from 10psi to a bit over 11psi.

Is this normal?

Will it effect my air/fuel mixtures / tune? need to retune?

I've got a power fc, fmic, full exhaust, manual boost controller, pod, in a 95 R33 series 1 making 255rwhp

I dont have a hand controller for the power fc.

I take the car to track days/skid pans so i wanna keep it reliable.

Cheers!!!!!

[SDEWY5]

doubt its ur o2 sensor, must b something else u have touched...mite b wrong i dunno

[allthewaytotheskyline]

02 sensor is only used during closed loop mode.

your 11 psi will be in top end of revs or when your booting it so it wont be the 02 sensor that did it.

[r33canada]

what kind of manual boost controller are you using, maybe it is suddenly is over boosting

[Don Dada]

funny enough i went up 1psi as well after changing mine and resetting the ecu... on a 26 though

[mad082]

as has been said, your o2 sensor only controls the closed loop mapping. this is light throttle. once you give it the beans it will drop into open loop which is much richer mapping. this mapping isn't altered by the o2 sensor.

however since you have a pfc, the mapping may be affected a slight bit more by the o2 sensor.

but all that still ignores one main factor. that is that the boost is controlled by thw wastegate. so my guess is that when changing the o2 sensor something was bumped in the wastegate actuator that has slightly altered the boost. this may have been the dump pipe flexing when loosening ot tightening the o2 sensor, etc

[Fletch]

i'm using a turbosmart manual controller but there is also an apexi boost controller hooked up in line too. thought that seemed a bit weird but it was like that when i got the car and my mechanic left it there after dyno tunig it and stuff. i'll get a pic tomoz and see what you guys think.

how sensitive are wastegate actuators? i might have slightly bumped it i guess when changing the sensor, but enough to alter my boost?

anyway, my main worry is that this extra boost has changed my tune and could harm the engine. does the power fc adjust its self or do i need to get the tune looked at and also try to figure out why there is more boost now.

only other thing different is that i dont have the turbo heat shield on. everything else it exactly the same. the manual boost controller is on the same setting as always.

cheers for ya help guys

[mad082]

the extra 1psi shouldn't really make any difference. there should be enough data in the mapping to easily compensate for 1psi extra.

[adamskill]

sorry for the hijack but i want to replace my O2 sensor, does anyone know the part number for rb20det?? repco had no idea. cheers adam

[mad082]

um, not sure if it is the same as a 33 (pretty sure it is though). if it is it should be listed in the book (i know for a fact that the r33 is listed in their current book) but if they are using an old book the 33 sensor is the same part number as a n15 pulsar SSS (2.0L) part number OZA395-E2

[adamskill]

um, not sure if it is the same as a 33 (pretty sure it is though). if it is it should be listed in the book (i know for a fact that the r33 is listed in their current book) but if they are using an old book the 33 sensor is the same part number as a n15 pulsar SSS (2.0L) part number OZA395-E2

cheers mate. the lad at repco thought it might be the same as a r31. i wanted to check first before i got it.

[Fletch]

the extra 1psi shouldn't really make any difference. there should be enough data in the mapping to easily compensate for 1psi extra.

cheers mate, just needed a bit of reassurance. now i can get back to flogging the titties off it.