the Brain

Please advice on O2 sensors

My new vans (04 chevy express 3500 6.0 engine) check engine light has been on for a month. Haven’t driven it much city fuel mileage is probably less than 10mpg that’s babying it.

Just had it scanned at autoZone. Result O2 heater circuit bank 2 sensor 1.

Man didn’t know which sensor it was.



1.I found a exploded view of a silerado on chevy forum. I believe bank 2 is pass.side

And sensor 1 is before the catalytic converter.true or false

2.should front o2 sensors (before catalytic concerter) be replaced in pairs?



3.should I expect a tad more power w/ new o2 sensor?

I have a new fuel & air filter plan to install next few days alone w/ oil & filter change

+ the front sway bar bushings, trans fuild, rear end fuild power steeriing and have coolant tested.



4.when my car needed o2 sensors it was suggested to don’t cheap out and get the Bosh.the Boshs had a bunch of extra wire I had to bundle it up and wrape it out of the way kindof a pita having a blob of extra wireing in a tight spot.

I ask bc I see a bunch of el cheapos available.

5.are front (or upstream) O2 sensors the same as rear (or down stream) O2 sensors



I’m glad that the scan didn’t have any random misfires so I’m gonna hold off on spark plugs until I get in touch w/ the previous owner. I suspect the SPs are the orginal

Iridium that GM says to leave in for 100K miles the mileage is 116K. I do know the procedure for SPs

Going though the wheel well for fronts and inside dog house for rear ones.

Thanks for advice

mountainmanjoe

The key word there is CIRCUIT.
Replacing the sensor isn't guaranteed to get rid of this fault.
Someone needs to inspect the wiring , and analyze the diagnostic data to find out the cause.



correct




no



maybe


OEM only.


compare the part numbers and see

the Brain

when you say "The key word there is CIRCUIT" if the O2 itself was all clogged w/ carbon deposits
the scanned results would say just O2 sensor?

as far as front & rear O2 are the same some of the el cheapos stated that.

thanks again mountainmanjoe for excellent advice as usalle. will report back w/ results.

edit: my car only has front O2s the rears where deleted.corvette O2 sensors are used for the F-bodys. the 4 wire was extra long if I remember correctly bosh expected me to cut & splice the 4 wires (no soldering )to needed lengh. can I expect a extra long wire w/ any of the bosh O2s?

mountainmanjoe

clean it

No. They never just say sensor. The computer has no way of knowing that.

then you will have a permanent check engine light.

MitchM

some mechanics on you tube also say they've seen o 2 sensor codes because who ver worked on the vehicle didn't get the o 2 sensor fastened in play tight enough .

mountainmanjoe

I would believe that. The sensor is calibrated for a certain depth in the exhaust stream. The position is important.


What was the exact DTC?

the Brain

not sure what the exact DTC was. all I recieved was the code p0155.
I recieved the Bosh O2 the other day hope I got the correct part.
thanks

mountainmanjoe

what?
DTC = Diagnostic Trouble Code
P0155 is a DTC.
put it in a web search
follow the troubleshooting
https://www.obd-codes.com/p0155

the Brain

that would be a touch of good luck just retighten O2 thanks
woopeis I'm not good w/ abbreviations

plan to install new O2 or retighten old O2
thanks

the Brain

unable to remove the O2 was able to dissconnect the 4 wire plug.
O2 is on tight in a tight spot. will have to order the tool socket w/ slite. even w/ tool it will be a pita.