Safety boost

[zxequalslife]

Hey guys,

I noticed last night that my boost gauge doesn't go all the way to the +7 and on my AVC-R it only displays about 0.37 kg/mm2 which is about 5 lbs of boost. I decided to run an ECU diagnostic last night because on my AVC-R it tells me my engine is knocking as well and I got a code 33 (Heated 02 sensor driver side). I know it's not knocking because the gas because I use 94 octane. It also only reads that it's knocking when the engine is warm. I'm also getting pretty crappy gas milage, $40 might get me 180 kms if the price of gas is low.

Could this be a chain reaction starting with the 02 sensor casuing the engine to knock and causing the ECU to go into safety boost mode?

Thanks,

[300ZXttZMAN]

well what is the price of gas ?

[zxequalslife]

About $1.50 a liter which is about $5.67 a gallon.

[300ZXttZMAN]

doesnt seem that bad about 7 gallons of gas getting you about 111 miles equals roughly 15mpg hmm . Do you smell fuel/ or fuel from emissions.... deffinatley change ur o2 sensors i changed mine about one month ago.... About 3 months ago I was driving and suddenly started smelling gas like not emission gas like straight up raw fuel unburnt so i quickly pulled over and raised my hood and i had gas leaking out of one of my injectors and it accually filled up the upper plenum with fuel so i went to my parts car and used the whole fuel rail and ordered new injector seals (early style) from nissan and that fixed it

i bought my car in november in 2010 (1990 z tt 5spd all original 107k miles)

[Ace2cool]

I would look into getting that O2 sensor replaced first. A failing O2 sensor will cause terrible fuel mileage, lost power, and, depending on how bad it's screwing with the A/F ratio, can trip safety boost.

Also, moving this to technical.

[zxequalslife]

Yea I do smell gas sometimes, but I'm pretty sure that's from the flaky-a** job the PO did on the gas cap...long story.

I'm pretty sure that replacing the 02 sensor is going to make a world of a difference. Could the bad 02 sensor cause the engine to knock?

[Ace2cool]

Depending on how bad it's screwing with the Air to Fuel mix, yes. If by knock you mean detonate, of course.

[zxequalslife]

The thing is I don't hear any pre-detonation when I rev the engine. I'm wondering now could it be the knock sensor thats faulty?

Also how the hell do u get the 02 sensor on the driver's side off? I can't even see it!

[Ace2cool]

It's right behind the turbo, unfortunately. Here's a pic of the stock precat, just for reference:

You can see where the bungs are for the O2 sensor.

If you had downpipes, things would be much easier, as most companies relocate the bung lower, for easier access:


As far as methods for getting it out, I would suggest one of the following ways:

1. Creativity
2. Flexibility

Good luck!

EDIT:

Here's a good visual representation from the FSM:

[zxequalslife]

Damn, I thought there would be an easier way... I actually dont have pre-cats or divorced downpipes. It's pretty much just a straight 2.5" tube thats welded to the testpipes. I can't even get my hand on the top of the turbo let alone trying to unscrew it. Woulde it be easier to go from the top?

[NolimitZ32]

try it from the top, I can get my hand with a tool down from the top and i'm not very skinny.

[zxequalslife]

So I think I might have found something. I don't think I'm in safety boost, the only reason why I thought that is because I was running 5 psi but my b/c was set to 11. I needed to remove the hose from the turbo to the intercooler and I found that the pipe underneath looks like it's missing a hose. There's a nipple and no hose attached. Here's a picture, does anyone know where this is supposed to be hooked up to?

[zxequalslife]

So I just thought of this, it probably has nothing to do with the 02 sensor. What probably causing the detonation is a bad A/F mixture due to the leak. Imagine if all my problems were solved with this one little nipple...just need to know where it goes.

[zxequalslife]

So I just thought of this, it probably has nothing to do with the 02 sensor. What probably causing the detonation is a bad A/F mixture due to the leak. Imagine if all my problems were solved with this one little nipple...just need to know where it goes.

[zxequalslife]

Anyone?

[Chase300]

yea it hooks up to your throttle body