blk_on_blk

It's true that when the knock sensor is triggered, the ECU will fully !Removed! the engine and lock you out of OD in the transmission, but I doubt that's the only code that does that. A misfire code may do the same thing. It's a protective mode so you don't damage anything, although it does make you run without overdrive and with the engine timing fully retarded. Add that to the hanging O2 sensor and I wouldn't drive it until the underlying problem gets resolved. I would advise you to get a cheap code reader/resetter off eBay or somewhere. That way you can reset the ECU and see if your overdrive comes back. That's a good indicator that your getting a code that's disabling your OD (and most likely retarding the engine timing). I would also speculate your may have blown your O2 sensor and be getting misfire codes possibly due to a clogged catalytic converter. When they plug, you get all sorts of back pressure in the combustion system. It could hold in unspent residual fuel (due to the retarded timing) and be igniting within the cylinder throughout the compression cycle, causing the misfires. If that is the cause, I would definitely not drive the vehicle until it's fixed. With the engine revved, can you feel much exhaust flow coming out the tailpipe? No or low flow would be a good indicator of a plugged cat. Lastly, the P0446 code is often a 'phantom code' in the 1999 RX300. I've had ours come on randomly for years... sometimes 6-9 months between it tripping. I just reset it and it rarely comes back. BTW, I would get that O2 sensor fixed before trying to troubleshoot anything further. Hard to isolate the cause of something when you have a known issue contributing.

Same here. I have a nearly identical vehicle ('99 RX300 FWD) and replaced my rear with KYB.

My '99 RX does the same thing sporadically. It usually clears itself up after a day or so. Or, I'll pull the battery cables, let it sit, then touch the pulled (+) cable to the (-) for a capacitive discharge for a few minutes, then reassemble. It's always cleared things right up. I don't know what it is, but it's sporadically glitchy.

I had a similar thing happen to our old 1995 ES300. We lost the engine (due to another problem) and our shop sourced a used, lower mileage long block for $400-$600... then it was just labor to take out the old one, put in the used long block, and then attach all our intake, exhaust, and peripherals. It wasn't that costly, and we had a car that ran like new after that! Rebuilding it would have cost more, taken more time, and then there'd be the chance the internals didn't get quite machined and assembled correctly, which could affect the life of the engine. If I needed to do it again, I'd take the same option as last time: have a reputable shop source a good used long block (which is the assembly including the block, pistons, crank, oil pan, and heads... all the critical seals and gaskets don't get monkeyed with).

Ah, the classic symptoms of the Idle Air Control Valve. Do a search on here as there are several (many highly detailed with images) DIY guides of how to clean the IACV. It doesn't need to be replaced, just cleaned (I cleaned mine with carb cleaner and an old toothbrush). It's essentially like an electronic choke, and the rotary valve gets coated in carbon and sticks. I'm 90% sure that's your problem. The other 10% is the possibility it's your MAF (mass air flow) sensor. If it is, that's an even easier fix. You can try cleaning it... in fact, cleaning the MAF would just be a good preventative. Be sure not to touch any of the sensor on the MAF, just spray it out with automotive electrical part cleaner. If you need to replace the sensor, they are roughly $100 +/- for the part.

Yeah, changing the battery in the FOB would be the first check... it takes a lot less energy to make the LED flash than it does to transmit the signal. Our old '99 RX300 sometimes doesn't respond to the key, and sometimes the response is delayed by 5 seconds or so, but most of the time it responds instantly... don't know why, but it's quirky. If you've only got one key, I'd keep working at that lock to see if you can get it to open... did you try slightly different insertion depths of the key, pushing in a little bit on the door to see if that eases on the mechanism? Can you get any movement of the key, or is it frozen when inserted? What works for us when the vehicle doesn't respond to the remote is to open the door manually and as the alarm goes off it always 'wakes up' and responds quickly to the key, which we use to disarm it. If you can 'joggle' the power somehow (i.e., press the panic button to get the alarm to go off, or somehow disconnect the battery for a bit... which I don't think you can get to from the outside), that might bring it back to life. I can't think of much else. Kind of stinks that Lexus would drop the rear key hole... one port of keyed entry is pretty limiting. Best of luck to you!

These are some of the top runners for quietness in a tire: 1. Bridgestone S-03 Pole Position 2. Yokohama AVS dB 3. Dunlop SP9000 4. Toyo T1-S A lot of the ride quality also depends on the tire profile... shorter side wall, larger diameter tires will inevitably ride more rough and loud. Hope this helps.

You should be able to find several nice step-by-steps on this process if you do a search on this site. Most of us have done this as some point or another. Just remember to move the cruise control cable mount to give you a little more room. Some I've found I can access better with a shorty box end wrench, others with a socket wrench (and a 1/4" socket driver fits back there better). Just take your time and work through changing them out... it's a little daunting at first, but once you've done it, you'll find it's not that hard.

Yeah, a lot can happen to an engine over 160,000 miles. You could have had a slight imperfection in a component over time that finally showed up and lead to oil starvation... or your screen got clogged, or a clog somewhere else in the system. Either way, sorry to hear about the failure. Although, $7500 is ridiculous! If your lower end is frozen from oil starvation, I would recommend sourcing a good used long-block (the full lower assembly including block and heads) and have a reputable shop do the swap. You should be able to find a nice, decent mileage long block for around $650 or so (probably less), then change it out of your vehicle (you keep all your intake equipment, fuel injection, etc.). We had an engine fail in our old ES300 (uses the same 1MZFE engine) and our shop was able to source multiple nice used long blocks in our area. They chose the one they liked and did the swap. The car was perfect after that... and nowhere near $7500. Take it to a good indie shop and get a quote for a long-block replacement. For most good shops, this is a straightforward job.

LOL... there's no way he ran hot soapy water THROUGH the engine. This has got to be a spoof-post, and it's not even April 1st yet.

We lost the engine on our '95 ES300, and had the engine swapped out for a different long block (we used our same injection system and all)... the car was like new when done and we sold it for a premium when we were ready to let it go. I've seen Camrys with ES engines, and vice-versa. They are pretty interchangeable. Just find a good one and you'll be back on the road in no time!

We've had issues with this, too (1999 RX300 with ~$175K miles on it). I've maintained the vehicle for the past 60,000 miles, and I've never had this issue until recently. We also have a fairly new transmission in the vehicle. At the first sign of this, I thought I should clean and IACV (Idle Air Control Valve), but then just drove it for another week or so, until it started to really, truly do the bucking and vibrations and started to stutter. I then pulled apart the whole intake system, cleaned the IACV, cleaned down in the throttle bodies, and from there it's been MUCH smoother and behaved. We still get strange moments of vibrations when stopped in D, and I'm guessing it could be an O2 sensor starting to act up, or possibly something I missed in the intake. I know it's not the injectors, for I replaced those about 30K miles ago. I would clean your intake system first and foremost. Go after cleaning out the IACV, and hose-out your intake system with spray cleaner. It should help clean up your system... may not totally resolve it, but it should help.

I remember reading a long thread on here about cracked manifolds. If I remember correctly, a truly (meaning problematic) cracked manifold triggers codes in the ECU (probably depends on where it's cracked). Plus, if you've got a crack/leak in your manifold, which is cast and quite solid, you'd have a leak/sound/issue all throughout the RPM range, not just at certain RPMs (plus it should get worse/louder with higher RPMs due to the greater exhaust amount/flow(or reduce once the engine is hot, due to thermo-expansion))... and I doubt it would have a rattle/hum/grunt sound if it were cracked... it's more likely to have a sharp 'popping' sound. We have a very similar vibration at about the same RPMs in our ES300, and it only occurs under load, and I'm quite sure it's exhaust related... just hitting a resonance vibration and rattling a loose mount or heat shield or something. I'd take RX_in_NC's input and have a muffler shop give you a quick check-up as a first start.

I totally understand (we had massive pouring rain here today, too). I would pull the battery, then close the hood and manually lock the vehicle. It'll sit there unnoticed for an hour or so and look totally normal, but that would give it plenty of time to defuse (some say it needs longer, but 30 minutes should be enough time... an hour will take out any doubt).

That sure sounds like an IACV (Idle Air Control Valve) issue to me. There are several DIY guides on here if you use the search function. I've cleaned the IACV twice on our 1995 ES300 due to nearly the exact same symptoms. Both times it started beautifully from there out. BTW, if you had a ignition coil that was bad, you would know it, and it wouldn't be sporadic... your engine would run really rough and with no power. If you engine is running smooth (once you get it started), then your coils are fine.