I;m looking on my 850 wagon, and the air pump that sits under the front left fender by the bumper was not hooked up. What does this pump do exactly? I have three dangling wires with connectors that connect to the fan relay on the pump itself...

 

AKA the SAS pump; it's an emissions device. You must have a '96 or '97?

They're kind of infamous for seizing up and stop working. As I understand it they only run for a short time during engine warmup?

If you need to get it working to get a smog cert, there are threads on how to repair them economically. Otherwise you could probably ignore it.

 

Yeah they only come on during cold starts to warm up the cat quicker. If you don't have emissions testing, you can ignore it if the check engine light doesn't bother you.

 

What year is it and do you have a check engine light ??

It's handy if you add the basic car info to your profile or signature.

 

Yes it's a 96' 5 cyl. non-turbo and I do have a check engine light on. I pulled two codes the other day:

1- I got an O2 sensor slow to respond code

2- and I also got a shift solenoid A malfunction...

I have to get this thing through emissions next month and am trying to figure out which shift solenoid "A" is...is that S1 or S2?

 

Is it O2 sensor 1 or 2 ??

Shift solenoid A should be S1.

 

The O2 sensor is sensor 1 bank 1...I don't know what that means. I thought there was only 1 sensor in the tailpipe behind the manifold. Thanks for the help. You guys have been great. This is my first time working on this car, and I think I am headed in the right direction. I have the battery, tray, air hoses, lower radiator hose, and all surrounding parts already disassembled and am now in the process of trying to get the trans. cover off so I can get to the shift solenoid. I am having trouble getting the bottom bolts out of it though...I think I am going to use an engine hoist and try to raise the right side of the motor up some so I can access the bolts. Do you think this will work?

On another note, I am stumped on the o2 sensor thing...

 

There is an "upstream" and "downstream" sensor. Sensors 1 and 2 respectively. IF, you had a V6 or 8 or horizontally opposed something then there would be two banks. Bank one is the bank that has the #1 cylinder in it. Since our engines have only one bank, bank 1 is all that will pop up with.

The upstream one is the more important one as the computer uses it to monitor the richness/leanness of the mixture. If it's slow or goes out then the computer is giving the motor the wrong amount of fuel. It will normally default to a richer mixture as it's safer for the engine. Your fuel mileage and performance will suffer.

The upstream is the one between the engine and the catalytic converter. The downstream is the one at the back of the converter.

The picture is not an 850 but it gives you an idea.

 

Thanks, this info. is AWESOME!!