Originally Posted by Nayov
Yeah, I'll start with the 'stat. I assume everyone's going to suggest OEM only which is about $14 for a genuine one on eBay so I'll do that and report back.
No, be careful about that. A lot of those are "fake." They are a thermostat, but not OEM. BTDT. Also check the rad cap. Changing the t-stat on these is pretty easy, it's just under the intake in the back of the V.
NAPA has an OEM thermostat (Tama) for like $30. The Stant and others are junk, don't use them. If you can find a truly OE one on ebay cheaper, go for it. But shop wisely.
OTOH, the OE thermostat is really robust and odd it quit at that mileage; I got about 300k out of ours before it failed (have an 03; have had a while and worked on quite a lot). Is the coolant still the toyota red or has it been changed? That often leads to rot in the system. If you were getting 31 on the highway, your burn was pretty efficient and it's very unlikely the cats are really damaged; they are pretty robust on these though not bulletproof. If after the t-stat and resetting the codes the cat codes come back, there are still ways to deal with that instead of pulling the headers off (the cats are one piece with the exhaust manifold). I don't even know if you can get the rear manifold off with the engine properly mounted in the car; it's crazy tight against the firewall - which creates others issues, of course. You really don't want to replace the cats because the aftermarket ones are junk and the OE ones for a pair will cost more than you probably paid for the car...
The sub-forum at ClubLexus is really helpful for these - a good place to look when you run into questions. Post there or feel free to pm me if you have q's.
One quirk (among others) is that that main CC relay in the under-hood fuse box generates fault codes in the CC module on the dash. If you notice the CC panel blinking at random times, there is an updated relay you can buy that fixes this. It's like $7 from Ebay. That looks like a nice car; must have been garaged most of it's life - no way the headlights would be remotely clear like that from Florida - even ours in WA were a nice toasted yellow in 10 years. I'd love to have another one with 100 to 150k on it right now; you made a good catch and it's probably well worth the flight and drive back. I fully expect to get 500k out of the one we have, and all the time running nicely and looking good (doing the proper maintenance, of course).
Resist the urge to use DexIII, WS, or MaxLife fluid in the AT. They are happiest with T-IV and it will minimize the notorious "clunk." You can get T-IV just as cheap as any fluid if you shop. Summit racing has a good deal always on it. A few months ago I found a great deal on Amazon for Idemitsu T-IV and bought a case or more, so I'm set for five years.
