Hello.

My 350z has a lot gasoline smell in the exhaust, and i'm not sure what's the problem or even it's normal.

As try to learn person(=don't know much about), recently I saw some video about fix the O2 and MAF sensor problem and I thought it might be my problem also. So I connected my cheap OBD2 bluetooth reader and this is what it shows.



So I believe there are 4 O2 sensors, 1B1 1B2 2B1 2B2, 2s are just shows voltage while 1s shows voltage and percentage. Also voltage of 2s are way lower than 1s, though it's changing a bit.

BTW, there are no check engine light and error code neither.

It looks like bad sensors, but it's hard to buying some parts in where I live, so I just want to be sure. Thanks in advance.

 

they may have been tuned out, or you have test pipes. crawl under the car and look

 

Nope. It has cats.

Turns out, O2 sensor 2s doesn't report STFT originally. So actually smartphone OBD2 apps were incorrect.

I'm not sure sensors are fine or not though.

 

For what it's worth the original O2 configuration is 4. Driver and Pass side, the "upstream" or upper sensors are designed to help with fuel volume delivery. The lower or "downstream" sensors have 1 purpose only- to monitor the efficiency of the cats and trip a CEL when efficiency drops below 96%.
If you smell raw gas in your exhaust it would be free and worth your time to check ALL the hoses and piping in the air intake for tight fit. Rule out mechanical issues before pursuing electronic solutions. GL!

 

do you know the previous history on the car, if it has been tuned, you may want to get it retuned by someone who know what the ****
they are doing. Some new tuners sadly think they can max out the Injectors even with stock intake application. If you are unsure on the tune, I would first try cleaning the sensors
for the sake of money, if that fails, replace the sensors, keep in mind it won’t be fixed
right away, it could potentially take a few miles drive to get the kinks settled. If this doesn’t fix your problem, I would see if there are some fatass injectors on it, but if it’s not sending any smoke out the rear end, sending any lights, or having any unusual residue in your exhaust tips, I want to say your fuel Input is fine, I’m kind of just assuming the worse for the sake of
your experimentation. If you have an aftermarket exhaust, and a cheap one at that, sometimes the smell is just something
you gotta deal with it. The headaches go away, and you get used to the smell lol. If you have a stock car tho your catalytic converters are bad, and if you’re getting codes for 02 sensors on a stock exhaust there is something
up than can be resolved. Not an issue I would worry TOO much about unless you start getting symptoms of smoke coming out your *** end, extremely reduced, gas mileage, or black
stains on your bumper.

 

Thank you guys for concern. Sorry for late reply.

So I visit the mechanic shop for change something else, I had chance for connect proper scanning tool. And there IS a code for O2 sensor(B1 S1), but that and all O2 sensors shows varying voltage in good range. So mechanic said it shouldn't be actual O2 sensor problem, maybe other tied part's problem but shows that code, though there was no time for detail analysis.

Anyway, like Dylan said, I have no information what so ever about the car history, maybe it's irregular injectors or ECU mapping something, but as long as it run looks OK, I will just drive and forget about it.

Thanks again.