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I've seen some folks showing the left side of the TB port being open vs plugged. When I look at mine, there's a hose connected to the port instead of a plug. Any idea why there's different configuration?
That's a vacuum port for the Vacuum Switching Valve (mounted to the upper intake manifold); it's part of the Evaporative Emission System. For what ever reason, mine is plugged.
I wonder why it is optional to connect vs plug. And more importantly, what are the effects especially on gas milage....
I'd like to think this will vary depending where you're located.
It looks like pur is in BC, and paulo is in Ca. You both may have a different setup, per emission standards, than most of us here in the states.
In the original pic, as Weld mentioned, the hose circled in red leads to the power steering ACV. The other hose (blue) is braided and leads back to the VSV.
The ACV hose on LS400s is connected to a port on the back of the upper intake. That may have carried over to the early 01 to 03 430s? If so, the port up front would be plugged...
Also, the ports are on the upper intake manifold, not the throttle body, and not necessarily related to gas mileage.
I'd like to think this will vary depending where you're located.
It looks like pur is in BC, and paulo is in Ca. You both may have a different setup, per emission standards, than most of us here in the states.
In the original pic, as Weld mentioned, the hose circled in red leads to the power steering ACV. The other hose (blue) is braided and leads back to the VSV.
The ACV hose on LS400s is connected to a port on the back of the upper intake. That may have carried over to the early 01 to 03 430s? If so, the port up front would be plugged...
Also, the ports are on the upper intake manifold, not the throttle body, and not necessarily related to gas mileage.
Thanks for the correction. I was looking at a Lexus service manual diagram. It's difficult to tell which hose nipple is referenced.
Thanks for the correction. I was looking at a Lexus service manual diagram. It's difficult to tell which hose nipple is referenced.
I am looking at the most left port on the top plane. A while back, I saw other FB discussion about mechanics leaving the port opens after services. Yet another internet photo shows a factory plug on the port. I immediately look at mine (one of the photos I look a while back) which is the attached photo with a hose going to the Evap side. That's what I wonder why many options. So to speak, if emission level varies by location, how the car run with or without this vacuum line routing variation I wonder? How one version carries a hose while other leave it plug yet the evap is the same. I am in BC but the car was an import from Spokane WA before I owned it. Perhaps still under WA spec..
I am looking at the most left port on the top plane. A while back, I saw other FB discussion about mechanics leaving the port opens after services. Yet another internet photo shows a factory plug on the port. I immediately look at mine (one of the photos I look a while back) which is the attached photo with a hose going to the Evap side. That's what I wonder why many options. So to speak, if emission level varies by location, how the car run with or without this vacuum line routing variation I wonder? How one version carries a hose while other leave it plug yet the evap is the same. I am in BC but the car was an import from Spokane WA before I owned it. Perhaps still under WA spec..
If you're still referring to the port/hose circled in red in your pic they are for a power steering valve. Not emission related at all.
It may also depend on the year model of the car...
throttle body plug vs hose - why different
