Road draft conversion on 1992 4.9L??
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4th Gear
Joined: Jan 2026
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Road draft conversion on 1992 4.9L??
I can post pics tomorrow. but im really curious as to what happened to my emissions system on my 1992 f150 4.9l. factory it came with the smog pump and egr. i bought the truck as it is now, i am not the one who did this to it. I'm also in a non inspection state and this is kinda just a project vehicle for me so I'm not super worried about getting it back to totally stock, but you'll see why I'm a little concerned if you read lol.
from what i can tell it looks like it's been road draft "converted"? being 1992 its way too new to have a road draft tube.... but theres a little slash cut tube just dumping onto the ground next to the transmission that looks like it's attached to a rubber hose coming out somewhere up by the valve cover/exhaust. the smog pump is still there but the hoses are gone and theres a different belt that doesn't go around it. did someone convert this from egr/smog pump to a road draft system or is the road draft tube part of the factory system? TIA
from what i can tell it looks like it's been road draft "converted"? being 1992 its way too new to have a road draft tube.... but theres a little slash cut tube just dumping onto the ground next to the transmission that looks like it's attached to a rubber hose coming out somewhere up by the valve cover/exhaust. the smog pump is still there but the hoses are gone and theres a different belt that doesn't go around it. did someone convert this from egr/smog pump to a road draft system or is the road draft tube part of the factory system? TIA
Tuned
Joined: Jan 2007
Posts: 338
Likes: 101
From: Salkum
My 1965 didn’t even come with a road draft tube.
Is there not an emission sticker on the underside of the hood showing hose routing? You should have a PVC valve in the top of the valve cover with at a minimum of a hose from that to the intake manifold.
Is there not an emission sticker on the underside of the hood showing hose routing? You should have a PVC valve in the top of the valve cover with at a minimum of a hose from that to the intake manifold.
Lead Driver
Joined: Sep 2002
Posts: 9,540
Likes: 2,032
From: North Texas
Valve cover has two ports, rear is the PCV supply to plenum and front runs to the air filter box with a tiny filter within.
Still have an O2 sensor? Leave the TAB and TAD electrically plugged in if still there, as well as the EGR position sensor, even if no vac lines to them. Keeps codes to a minimum.
Snap pics if you have time
Still have an O2 sensor? Leave the TAB and TAD electrically plugged in if still there, as well as the EGR position sensor, even if no vac lines to them. Keeps codes to a minimum.
Snap pics if you have time
Cargo Master
Joined: Mar 2002
Posts: 3,132
Likes: 219
From: W (BY GOD) V
I'm also in a non inspection state and this is kinda just a project vehicle for me so I'm not super worried about getting it back to totally stock, but you'll see why I'm a little concerned if you read lol.
The crankcase has to be vented and road draft is not the correct way.
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