01 Bravada SES light

01 Olds Bravada. 4.3L TBI. Just rolled 100k and so I changed the plugs and wires. After driving for about 3 hours the SES light came on. I checked all my sensors to make sure they were plugged in, in case I forgot to reconnect one after changing the plugs. (MAF sensor plugs, oil hose that goes into TB, etc.) I haven't been able to get to a shop or an auto parts store to pull the codes yet. I pulled the battery cable off for a few minutes to clear the codes and see if it came back. I forgot to put the hose on on the back of the air intake right above the TB. I figured that's what caused the light to go off. The code came back ofter about an hour and a half of driving. Any ideas off the top of your head? I will post codes as soon as I get them. Thanks.

01 Olds Bravada. 4.3L TBI. Just rolled 100k and so I changed the plugs and wires. After driving for about 3 hours the SES light came on. I checked all my sensors to make sure they were plugged in, in case I forgot to reconnect one after changing the plugs. (MAF sensor plugs, oil hose that goes into TB, etc.) I haven't been able to get to a shop or an auto parts store to pull the codes yet. I pulled the battery cable off for a few minutes to clear the codes and see if it came back. I forgot to put the hose on on the back of the air intake right above the TB. I figured that's what caused the light to go off. The code came back ofter about an hour and a half of driving. Any ideas off the top of your head? I will post codes as soon as I get them. Thanks.

First off a battery disconnect will not clear codes.
Is light blinking or on steady.
Can you feel any engine miss?
Hose off may have set code.
You will need to get the codes and clear codes and drive it and see if any codes come back.
Get the codes checked and cleared and rechecked and post back the codes before and after code clear.
And someone will help you.

Alright,
I pulled the codes at the Auto Zone. It was a P0140. Which is a 'Secondary Air Injection System' code. I have no idea what that is. I cleared the code and put a new air filter on and cleaned the MAF sensor. I have been driving it for a couple hours with no codes yet. I hope that this is the end of it. That's what I like. Easy fix. I can't really have my baby breaking down on me. :lol2: Thanks for the help. If it comes back, I will let y'all know.

i think "secondary air injection system" has something to do with the air pump?? im not 100% sure

P0140 Oxygen Sensor Circuit No Activity Detected (Bank 1 Sensor 2)

Alright,
I pulled the codes at the Auto Zone. It was a P0140. Which is a 'Secondary Air Injection System' code. I have no idea what that is. I cleared the code and put a new air filter on and cleaned the MAF sensor. I have been driving it for a couple hours with no codes yet. I hope that this is the end of it. That's what I like. Easy fix. I can't really have my baby breaking down on me. :lol2: Thanks for the help. If it comes back, I will let y'all know.

You are welcome and thanks for posting back how it went.
As said code 140 is a 02 sensor code.
If it comes back check your 02 sensors for working right.

This is a good one. SES light is back on. It isn't and wasn't flashing. I went to start it before work and it revved to about 2500 RPMs then dropped fast and started idling like crap. It then died. I let it sit for about 30 seconds and tried again. This time I didn't let it die. I held it at around 3000 RPMs until it warmed up a little. I let it go and it 'idles' at about 1200 RPMs. One person told me MAF, another said vacuum. WTF is it? I'm leaving this weekend for two weeks and letting a friend of mine use it since her car is flat broke. I need to get this fixed ASAP. Any suggestions? I appreciate everybody giving me advaice and suggestions. Thanks HeavyJ and MT-2500 for the O2 sensor tip. Just to be 100% sure, the Bank 1 Sensor 2 is a downstream sensor correct? How many O2 Sensors are there on an 01 Bravada?

Took it to a Goodwrench service center and had a diagnostic done. It was a leak between the tb spacer and intake. Word of advice to those who think it's great to put one of these in, don't. It doesn't improve a thing and it actually throws the sensors off track, sending false signals to the ECM. Your fuel economy will be better without one. I went from getting about 20-23 with the TB spacer to 25-28 going 60 MPH on level road. I can deal with that kind of increase. Any how, the SES light is still on for the O2 sensor, but I will change that when I get to it. However, I still need to know which one bank 1 sensor 2 is though. Thanks y'all.

Codes do not say to replace sensor but to check things out.
Was the codes cleared and what came back after clearing?
We need the code no to be able to help you.
Post back code no.

The code is the same as the first one. P0140. The code came back after the service center cleared the codes for the intake leak. It's hurting my gas mileage a little but it's not horrible. Thanks for the info and help.

The code is the same as the first one. P0140. The code came back after the service center cleared the codes for the intake leak. It's hurting my gas mileage a little but it's not horrible. Thanks for the info and help.

Code P0140 is HO2S sensor voltage is within bias range of 350-550 millivolts.

Basic the heater circuit is not working right.
Could be wiring or plug in or bad heater circuit in sensor.

To test you need a engine capable scanner to read out the o2 sensor readings and O2 sensor heater voltage readings.

May drop mileage some but the 02 sensor heater circuit kicks in when engine is cold or long extended idle.

How much is mileage down?

The mileage is down only about 2 to 3 MPG but with gas prices being so unpredictable I'd like to get the max out of it. I'm getting about 23-25 on the interstate right now. I've already purchased an O2 sensor but i'm not really sure where it is exactly. I think there is about 3 of them on this SUV but agian, I'm not sure which one. If I changed it would it fix the heater issue? Or is it a wiring problem? I do get caught in traffic alot so I do a fair amount of idling. Probably about 30 to 40 minutes on an average day. More if the traffic is bad. I know that it's hard on the engine but I can't really start and shut off the engine while i'm in traffic. Again, thanks for the help.
~JD~

The mileage is down only about 2 to 3 MPG but with gas prices being so unpredictable I'd like to get the max out of it. I'm getting about 23-25 on the interstate right now. I've already purchased an O2 sensor but i'm not really sure where it is exactly. I think there is about 3 of them on this SUV but agian, I'm not sure which one. If I changed it would it fix the heater issue? Or is it a wiring problem? I do get caught in traffic alot so I do a fair amount of idling. Probably about 30 to 40 minutes on an average day. More if the traffic is bad. I know that it's hard on the engine but I can't really start and shut off the engine while i'm in traffic. Again, thanks for the help.
~JD~

As said you need a good engine capable scanner read out and good volt/ohm meter to see if senor bad or heater circuit or wiring.

4 - 02 sensors on yours..

Bank 1 sensor 2 is second sensor back on bank one exhaust pipe.