K8sdad

Just posting a success story and a thank you to contributors. You are doing some good here.

Back Story:
2001 RX300 - 170K miles

1. For maybe the last 7 years and 100K miles or so, VSC Trakoff and Check lights come on intermittantly. Throw P1130 and P1150 errors. Lights stay on a few days then go off for a few days. Never caused noticeable problem so finally left them alone. Dealership could not troubleshoot and to their credit did not recommend replacing both valvles.
2. About 2 months ago, noticed new rattling (gringing? growling?) noise upon mild acceleration (ie coming up to speed from a stop sign or something).

Last week engine misfires badly. P1354, P0302, P0304,P306. Based on my searches pf Club Lexus I decide to try and fix it myself. (I am no mechanic, but handy, and have some tool.) Great and helpful posts on this topic. Ordered part from Amazon, followed BearsLexus DIY and replaced OCV valve myself. Moving some hoses and getting my hands in there caused some cussing, but some 40 minutes and some skinned knuckles later, job done.

Results:
1. Engine misfires completely gone. Running really smooth.
2. New Rattling sound on mild acceleration is gone.
3. Only been a week, but the VSC, tracoff, and check lights have not lit up even once...and as I said, that had been going on for years.

Many many thanks to all ClubLexus contributors

JAB

Interesting. When my OCV failed, it was sudden, without intermittent disruptions as you describe, and could not be ignored - car was borderline undriveable. Replaced without any difficulty and has been troublefree ever since.

K8sdad

Oh yah...once it failed it could not be ignored. Had to replace immediately. Other problems may or may not be related... But now they appear to be gone! Coincidence? Could be