Truck is a 1991 302 bronco, Title says it all,truck runs semi rough, have been driving like it is for the past 600 miles since I bought it but have now started working on a lot of stuff. Just replaced timing cover and chain. Now I replaced egr and sensor because of CEL and still no help same codes I believe 332 and 317. all I remember is thermactor not engaging and EGR Something. Well there is a loud whistle from under hood. Also there was a yellow vacuum line behind the upper manifold/plenum that I believe is to the TAD that is unhooked I tried going behind there with my hand and plugging it in and snapped the line. So my question is where does the line end plug in to?? I can find where it comes from on the right side but can not find where it plugs into the rear of the intake manifold.

 

Any vacuum related routing should be on a sticker in the front of the engine compartment. My guess is broken vacuum lines are contributing to a vacuum leak and will cause a lean condition that the computer is compensating for and this is the reason for the roughness.

 

I would just replace the vacuum lines with new hose. Following the diagram on the hood, replace them one at a time. 5/32" is what I used on my 1993 302, took maybe an hour. It also required two tees.

 

My 95 f 150 5.0 has a air divertor behind the plenum and it plugs into the top of it but the color is a light brown in color or beige and I believe the yellow comes from the rear TAD bottom outlet and goes to bottom of air divertor valve ?

 

Nope sorry wrong suggestion as it is from rear TAD it is from the front thermactor air unit the top port hole black line goes to the bottom

 

I have an 88 Bronco XLT 351w and I just replaced all my vaccum lines with rubber hose it is running a lot better. The light brown, beige goes to a valve on the left side below spark plug level and the nipple was on the bottom of the valve. I found it easier to get on the driveway and attach it from underneath. At least that is what I found on mine.

 

I stopped caring about the light after replacing the egr position sensor and valve. When I changed a couple lazy lifters I was able to hook up the thermactor the right way with intake manifold off. Still had egr light, so I changed egr solenoid and all is good now. First time since I have owned the truck I ride around with no codes now. Yayyyy