Help P1139??

[Silver Blue '97]

Does anyone have any info on this code (P1139)?

Thanks in advance.

[maxwedge]

Check this link, of course we guessed at the year! Direct fom GM, don't see the code though, http://service.gm.com/gmspo/mode6/pd...2000file10.pdf

[apollo7879]

The '96 book says :
DTC P1139 is designed so that if the O2 sensor is slow to respond
to changes in exhaust content,then DTC P1139 will set.
There are 4 O2 sensors in the '96 4.0L

If the sensor is bad it is located under the passenger compartment
It is bank 1 Sensor 2, The pre-converter O2 Sensor

[Silver Blue '97]

[quote=apollo7879]The '96 book says :
DTC P1139 is designed so that if the O2 sensor is slow to respond
to changes in exhaust content,then DTC P1139 will set.
There are 4 O2 sensors in the '96 4.0L

If the sensor is bad it is located under the passenger compartment
It is bank 1 Sensor 2, The pre-converter O2 Sensor


Thanks apollo7879 for the info. How can tell if the sensor is bad? Should I just change the (auto zone $69.00) sensor? If I cleaned the egr valve would that do anything?

Sorry for all the questions. Thanks again

[apollo7879]

I don't think the EGR valve will clear this code.(But if you haven't ever cleaned the valve you should anyway)
Does the car run ok, or does it seem to surge & run a little rough.
That is the condition that I had(along with the "check engine lite")
and I think i had the same P1139 code. At any rate I replaced the
sensor & it solved my problem.
The sensor is easy to change, with the loaned sensor wrench from AutoZone.
I guess the question is: how is the car running?