mandyfig

This is a very interesting thread. I will look at my VSV as well and will clean it. And see if I get a smoother idle (it is already smooth but will do a before and after). Whoever came across this DIY, kudos to you!

ls430w140

Amayama or amazon should be safe enough if you find a reputable seller in the marketplace. Taking into account relatively low price of the VSV, I suggest to go for it especially after doing your best effort of diagnostic. If nothing else is showing up, go for it. This tiny valve plays a huge role in the car apparently.

Bocatrip

Ls430w140.......I had a thorough conversation with my local Lexus shop foreman who I know since purchasing my car many years ago. He mentioned that since my car is so old, there are less modules to monitor the different systems of the car as the new cars now have. PO440 could almost be anything, even a lose fitting of a vacuum hose on any connector. The diagnostic computers Lexus uses can shut down certain sections of evaporative emissions system in order to isolate it's origin. There is a $99 diagnostic fee (applied to any repair) and he assures me that more than likely they will find the culprit however........the CEL for the PO440 code in my scenario is basically an environmental issue that is not affecting the performance of my car. Gas mileage is fine as well as performance. I'm still deciding on my next move. I am also waiting for the CEL to reappear after I cleaned the VSV. So far it's been a few hundred miles and about a week. I'm fairly certain it's on it's way! The VSV is $68+ tax which is no big deal. If the diagnostics point to the charcoal canister I will be abandoning the project. To be continued.

Bocatrip

What role does part number 25860-50121 play in all of this? It is also described as a purge valve. Can't this valve also cause issues and why aren't we looking into it as a culprit? I believe Lexus has it's cost at $78. Is it hard to get to and can it be tested?

toddmorr

cleaned my VSV valve with first liquid wrench, then throttle body cleaner...just sprayed a bunch of that in there, shook it around. No codes before, no codes after. It does feel surprisingly smoother. Impossible to say anything re gas mileage.

ls430w140

lmao. Sorry, just didn't know the name of this penetrating spray...

Welcome to VSV Cleaning club ).

Bocatrip

Has anyone actually replaced the VSV with a new one to find it fixed and or improved their particular problem and/or permanently kept the trouble codes off?

Peacebay

I would caution people against using penetrating fluid to “clean” this vsv. The only reason wd40 would be acceptable is because it contains solvent. A penetrating fluid has hardly any cleaning properties.

toddmorr

agree, that's why I first used the Liquid Wrench, then actually cleaned it with Throttle Body cleaner.

StanVanDam

I replaced EVAP VSV (25860-50100) with a brand new one. In conjunction with a fresh oil change at my 8000km interval (just hit 168,000 km), using a 5L jug of Castrol Syntec 5W-30 (0.5L overfill), and draining 1.6L of T-IV and replacing with 2 x 1L jugs of T-IV (2nd time I've done this over 24,000kms, ~0.8L overfilled), a new unused OEM MAF and PCV valve and grommet installed a few months ago, and 225/55/17 tires at 35psi on OEM chromes, I got 8.9L/100km (26 mpg) on a 650km roundtrip drive, 90% highway, average speed 100km/h with several full-throttle passes, this drive normally averages 10.0L/100km (23.5 mpg).

Original spec in Canada was 8.8L/100km highway (http://www.autos.ca/car-test-drives/...2-lexus-ls430/), so I'm pretty close with 8.9. Engine air filter has 24,000kms on it and not cleaned since installation, still on original spark plugs and original 3 of 4 O2 sensors (RH front has 80000km less mileage than the other 3, still Denso OEM). Coolant has 6 years and 46500km of use, due for a change. Throttle body and plate was cleaned a year or 2 ago.

2021 update (2 years later): hesistation/acceleration lag is not related to this part. This part can give a very incremental increase to fuel efficiency, and if the old one is cracked/leaking, it can eliminate gasoline smell in front end.

atlcal

Only two tanks of gas since I bought my 06 UL w/ 135k, and mileage on the dash has settled around 16.5. Had some spare time so I popped off the valve and cleaned it up with some WD40, so far, it's picked up .5 MPG in less than a quarter tank with no change in my driving habits. And I must be leading a charmed life because the hoses came off with no issues and the connector did not break

peafarmer

I have a 2003 LS430, 240K miles that has codes P0442 and P0446. I thought I would start my troubleshooting at the VSV. I removed the electrical connector to the VSV and am measuring 11.7 V with the ignition ON, not started. I removed the VSV and see that the hoses to it are cracked, so I think I could have a small vacuum leak on one or all of the hoses. The VSV is closed with no voltage applied. I took the VSV and applied 12.8 VDC from the battery and heard a click, and the VSV opened...I could blow air through it.

So, I thought: the VSV is good, time to troubleshoot elsewhere, but decided to make sure that the VSV opened with the voltage from the connector. To my surprise, when I connected the electrical connector to the VSV and turned the ignition ON, the VSV did NOT open.

So, at this point, have I found my problem? Is my VSV bad? I saw videos of mechanics using a 9 Volt battery to check these valves. Also, if my VSV is not operating as it should would this cleaning process perhaps restore it, or is it too far gone...just replace it?

Thanks, hope somebody has some experience that will help.

Andy

Bocatrip

Is your CEL on? Do you have any trouble codes? Have you tried an OBD2 scanner for any issues? I would go that route before throwing money at your car without certainty of any bad parts. The vacuum hoses are relatively easy and inexpensive to replace.

peafarmer

Yes, CEL is on, codes P0442 EVAP system small leak, and P0446 EVAP system vent control fault.

Bocatrip

Sorry about not noticing you mentioned the codes. I'd start with the small stuff, gas cap, and all those small vacuum hoses near the VSV. Did you perform a smoke test yet? Clear the codes and check the mileage of how long and how many miles if/when the light comes back on. The Evap system on our older cars can sometimes be difficult to find. I've been working on mine for quite some time with the PO440 code and CEL.. I've changed the cap, all the vacuum hoses, cleaned the VSV, performed the smoke test (showing no leaks) etc. I've been driving with a half a tank of gas for the last few fill ups until recently. So far the CEL has not come back on and it's been almost 800 miles. I'm not overly confident that it's resolved. Good luck with yours and let us know how you make out.