D16Y8: Intake sensor and hoses question

[cadieux_j]

Quick question that has always bugged me. On a OBD2 D16y8 engine there are 2 hoses, and 1 sensor on the intake before the throttle body. 1 hose is a breather from the valve cover, the other is an idle assist hose that really doesn't seem to make a difference if its connected or not, and the sensor is, what I am guessing is a air sensor. Now when I look at most D16 setups, none of these seem to be connected to the piping before the throttle body. i know the breather can be fit with a filter to vent to the atmosphere, but what about the 2 others? are they not useful on an OBD1 ecu or something?

 

[RonJ]

I think you are talking about:

Hose for breather
Hose for FIA control system
IAT sensor

I think all should be hooked up for an OBDI system.

 

[got traction]

Quick question that has always bugged me. On a OBD2 D16y8 engine there are 2 hoses, and 1 sensor on the intake before the throttle body. 1 hose is a breather from the valve cover, the other is an idle assist hose that really doesn't seem to make a difference if its connected or not, and the sensor is, what I am guessing is a air sensor. Now when I look at most D16 setups, none of these seem to be connected to the piping before the throttle body. i know the breather can be fit with a filter to vent to the atmosphere, but what about the 2 others? are they not useful on an OBD1 ecu or something?

the sensor you are talking about is the IAT (Intake air temperature) Most people just let it hang, but keep it away from a heat source, other people drill into the intercooler piping and attach it.

 

[Szady]

the sensor you are talking about is the IAT (Intake air temperature) Most people just let it hang, but keep it away from a heat source, other people drill into the intercooler piping and attach it.

Will letting it just hang cause a CEL for running too rich if the car idles for awhile?

 

[RonJ]

It's best to install the IAT into intake as it was designed to be. Generally, I don't think you'll get an IAT code if it is left hanging. I would think the engine would run lean if it's left hanging or touching a hot engine part.

 

[Szady]

It's best to install the IAT into intake as it was designed to be. Generally, I don't think you'll get an IAT code if it is left hanging. I would think the engine would run lean if it's left hanging or touching a hot engine part.

Well, yea. But in my current situation, my intake had to be modified, and it dosent have a hole for the IAT sensor. So, I just left it dangling for now, and I randomly get a fuel system code now that i never got before. I thought since A/F ratio's are effected by air temp, that the sensor might have had something to do with it.

I just gotta drill a hole in my pipe for it....Im just lazy this time of year. Cold sucks...

 

[RonJ]

and I randomly get a fuel system code now that i never got before.

Are you getting CEL code P0172? Don't you have an exhaust leak that is causing this code?

 

[got traction]

Will letting it just hang cause a CEL for running too rich if the car idles for awhile?

shouldnt. i've had mine hanging for 2 years...never thrown a code

 

[Szady]

Are you getting CEL code P0172? Don't you have an exhaust leak that is causing this code?

Na, its code 45. Dunno what that is for OBD2 codes. Thats what the CEL flashed at me. It happened while the car was idleing for about 20 minutes so I could set the ignition timing. Im just assuming its running too rich....

I reset it, and it hasent come back yet. Then again, I havent driven it much since....

 

[RonJ]

Na, its code 45. Dunno what that is for OBD2 codes. Thats what the CEL flashed at me. It happened while the car was idleing for about 20 minutes so I could set the ignition timing. Im just assuming its running too rich....

I reset it, and it hasent come back yet. Then again, I havent driven it much since....

If the code doesn't come back, then don't worry about it. Code 45 means either P0171 (lean) or P0172 (rich). You'd have to pull the code with a scan tool to know which it is.