OBD1 Test


New Member
Mar 28, 2010
Can anyone help me? I have never run these tests and am not very good at reading the codes.

I did the KOER test and got a 314. Is this an o2 sensor code? Says bank #2 sensor. Is it bad or did i do the test wrong?

Also I had a little trouble reading the codes during the KOEO test. Will someone take a look and gimme a hand?

YouTube - KOEO

YouTube - KOER
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Well, code 111 means that you passed the KOEO. The code is repeated twice, then a separator beep, then any code stored memory are repeated twice. 111 always means OK or No codes.

The KOER 314 code means part of the AIR system is not working. Likely one of the small colored plastic lines leading into the passenger fender are broken or disconnected. There are two plastic lines (one red, one green) hooked up behind the throttle body at the back of the engine. Thrace those and you'll find two other plastic lines that hook up under the air intake, make sure those are good.
First I wanna say thanks for all the help here at this site. This is my first mustang, got it about a month ago and the help here is awesome.

The plastic lines your talking about, what do they connect to?
There are a total of four plastic lines in this part of the system. The red and green lines connect to the EGR (part of the emissions system) and the intake. The other ends eventually connect to some solenoids in the fender. The remaining two connect to emissions parts that pump air into the backs of the cylinder heads and the catalytic converters. Engine vacuum comes in from the line hooked up into the intake (green, I think), and the solenoids control if that vacuum gets to the three components. It's a weird setup, but works pretty well.

Take the intake hose off and you'll see the plastic lines a bit better. It's likely one has cracked or broken, so the computer can't control those parts.
I checked and finally found the green and red hoses. None of them are cracked or visually broken. If i pull either of those hoses off should i feel the vacuum there?

On a side note last week i did find a broken hose off the tree on the right side near drivers side firewall and fixed that. Also I installed a CAI about 2 weeks ago. anything to do with it?
The vacuum is generated by the intake, so if you pull off the hose on the intake while the engine is running you'll feel something. The one on the EGR won't get vacuum until you're cruising. The error code has to do with one of the two other lines under the CAI. The red & green hoses lead to a rubber juncture with two other hoses, so 4 hoses go into the fender. Trace the other two and see if either of them are broken.
Well, I started checking for the broken green or red line and both of them cracked just moving them. I dont know if they were broke already or I just broke them. I will have to replace both of them now. Same thing happened to the vacuum for the a/c on the tree on the right. I touched them and crack.
If I replace those lines and it still doesnt clear the code, what next?
Well i replaced both lines from the intake and the egr. I replaced the two hoses all the way down to the connector under the CAI. I ran the car and all seemed well. After about 5 min of driving my check engine light comes on now. It didnt before. I checked all the hoses and they are still connected. I ran again and light comes on. I pulled the codes again and still getting the 311 but getting a 314 now. I ran a soft vacuum hose instead of the hard lines like before. Is this going to make a difference? Also how do i get to the solenoids? Take the fender off?
311 and 314 are the two AIR codes you can get if there's a problem with the hoses you replaced. Make sure you don't have the hoses switched between the EGR and the intake (the old green and red hoses). If they're switched, you won't have any engine vacuum at all.
Correct, red goes to the intake and green is to the EGR. Is it possible the line is collapsing under vacuum? To get to the solenoids, it's easier to take off the fender liner rather than the fender, but you'll also need to remove the wheel.