92 bravada O2 sets off SES lamp constantly

[ericn1300]

the O2 sensor used to set an error code occasionaly back home, but now it's driving me nuts.

yesterday i drove 650 miles thru a winter storm on my way to california. normal speeds on this trip are 70 to 85 mph depending on whether it's two lanes or four. at these speeds i only see the SES light come on when i had to slow down for traffic and wait for a chance to pass.

on this trip i had to slow to 50 to 60 mph because of weather. when ever i slowed to about 50 the SES would come on and go off again as soon as i picked up speed again. on and off for 13 hours. and i still have over 1200 miles left before i finish this trip and get home.

can anyone tell me where the O2 sensor is? can it be removed easily and cleaned or do i need to replace it.

[maxwedge]

What is the code, first of all?

[Chris Stewart]

Max is right, do yer diagnostic...
Code 44 is O2 sensor sensing lean condition....low fuel pressure/blocked or iced filter.

Code 45 is O2 sensor sensing rich condition...leaky fuel lines inside the intake manifold/CPI pressure regulator.

[ericn1300]

code 13, indicates that the oxygen sensor circuit or sensor was open for one minute while off idle.

this is the only code set since clearing the codes after fixing the egr problem 6,000 miles ago.

[Chris Stewart]

The O2 sensor is on the exhaust pipe right next to the transmission and is difficult to see but not hard to replace...I let my fingers do the looking when I replaced mine for a code 45...I later replaced the fuel lines inside the intake then replaced the CPI soon after.

[blazee]

"CODE 13

Trouble Code 13 indicates that the exhaust stream oxygen-content sensor (O2 sensor) is not responding as expected. When cold, the sensor is 'biased' by the ECM to about 450 millivolts. Before it warms to at least 600 deg F (315 deg C) it acts as an open circuit and when the ECM reads it, it reads the 450 mV bias. The ECM expects the sensor to warm in a short period of time and begin sending its own voltages. The general conditions for this code getting set are:

- engine running at least 2 minutes

- coolant temperature at least 50 deg C (122 deg F)

- O2 voltage not fluctuating (i.e steady between 350 and 550 mV)

- TPS signal above idle

- all above conditions met for 60 seconds

Typical causes may include:

1) Defective or degraded O2 sensor

2) Deposit-contaminated O2 sensor (running leaded fuel, RTV silicone deposits etc)

3) Corroded/defective O2 sensor connection

4) Defective sensor ground circuit

5) Defective connection at ECM

6) Defective ECM

NOTE: If codes 21 and/or 22 are also present cause '4' above should be checked first."

[ericn1300]

thanks guys. i'm at disneyland right now. will be driving to a friends in San Francisco (400 miles) next later this week, he's got a good shop I'll try to get it fixed there before going back over the mountains.

so far this trip i've drivin over 1250 miles and the bravada runs like a dream except this little prob. i could really feel the smartrak kick in on the snow and slushy sections. the first portion of the trip probably would have taken two days in my old rig.

[ericn1300]

while still at Disneyland i went on line to find a parts store in the area that had an O2 sensor in stock. the web site asked me if it was before the cat converter or after so i went out to the parking lot to check if Chris' info was correct. i crawled under the car and determined he was right just as security showed up. ordered out from under the vehicle, two guards lead me off to their vehicle for questioning while four others set up a perimeter about five cars away from my Bravada and waited for the Anaheim PD to show up with their bomb sniffing dog. the dog went all around my Bravada, not finding any bombs but he did pee on the same tire my dog always does too. they were not amused when i laughed at that so they opened the doors and let the dog run through the vehicle snorting and walking thru all my stuff. it took about two hours of id check and registration checks before we were done.

i got into SF late last night. went by my buddy's shop today 12/24 to see if he could squeeze me in. he said they had a few things to work on first and led me into the shop. turns out they were working on a bottle of wild turkey and eggnog. a good time was had and they did hand me roll of black tape to get me by until next week.

Merry Christmas all, I'll keep you filled in.

[ericn1300]

The main reason for the O2 sensor going nuts on me this trip turned out to be the Oxygenated gas I fueled up with in north Nevada. Seems they use this blend in the the winter for ecological reasons.

Anyway, I finaly got the O2 sensor changed while in San Fransico. My load leveler (AKA known as the wife) gave it a test drive by accident on the same day when she missed the last exit on the freeway and crossed the Oakland-Bay bridge. Good thing she had her purse along with her, cost her a $3 toll to get back.

[Chris Stewart]

Coool, I'm glad your O2 sensor and Mrs.Eric are doing fine.

[ericn1300]

Thanks Chris, yeah the "load leveler" is doing fine. got her drivers lience back after 6 months my driving her around. after the bridge incident i treatend to get a bottle of blond hair dye since she's been acting that way lately