monarch

Yes, stay alive so you can come home and fill your Lexus with the oil you defended:IRAQ'S PIPELINE TO CALIFORNIA Iraq has historically been a big supplier of California's crude, accounting for one fifth of all the state's imports in 2002. The spigot was cut when the United States invaded Iraq in March, but it was restored in August. -- Sources of oil in California Foreign imports 30.3% Domestic 69.7%. -- Sources of foreign oil imports Iraq 20.1% Saudia Arabia 19.5% Ecuador 13.7% Mexico 8.4% Angola 8.3% Argentina 7.3% Yemen 3.7% Australia 3.5% Others 15.4% Source: California Energy Commission

Could be way overdue for a new fuel filter, air filter, spark plugs, distributor caps, distributor rotors, spark plug wires and oxygen sensor. Could also need a throttle body cleaning and a change of transmission fluid using Toyota Type T-IV.

You're right - I forgot there is one pre cat sensor per exhaust manifold on the V6.

There is only one oxygen sensor you need to replace - it's the one in front of the catalytic converter. If you go to this website http://tinyurl.com/njqgt and type in "oxygen sensor" in the space for keyword, you'll see a new front sensor for a Federal emission ES like yours is about $114.00 with free delivery via UPS Ground This genuine Toyota sensor will look and fit perfectly, just like the factory original one and will last just as long. And after front sensor replacement, fuel economy should improve noticably. The rear sensor (behind the catalytic converter) should last many more years before it needs to be replaced. Beware the sensors available from aftermarket websites like oxygensensors.com may not be identical in every respect so the functionality, reliability and durability of the sensor may not be as good either. The aftermarket websites also provide generic replacement advice rather than Toyota specific advice, so that's why they will say you need to replace the rear sensor too. Also beware some people will likely say you could buy a "universal" sensor for only about $70 from aftermarket websites (or $23 on ebay) and that using a universal sensor will not compromise functionality, reliability and durability. But then they will tell you that to install a universal sensor one needs to solder, splice, heat shrink, crimp, tape, etc. 3-4 wires. So who knows how long a home made wire job using hardware store electical supplies will stand up to summer heat, winter cold, fog, flooding rains, road dust, road debris, etc ??

nc211, on your way northwest up to Santa Barbara, on highway 101, you'll see more Lexus's and Infiniti's on the road that you have probably ever seen anywhere else in the USA before, particularly around the ritzi towns of Calabasas, Thousand Oaks, Westlake Village, etc. Or, if you take the coast highway #1 to Santa Barbara, you'll also see Lexus's and maybe Lamborghini's and Ferrari's around the movie star towns of Malibu and Pacific Palisades. In Santa Barbara Lexus's and Porsches are very popular At Lexus.com I think you'll see there are over one dozen Lexus dealers in the Los Angeles area.

According to Consumer Reports, a near new LS400 filled with conventional oil, factory filters, facotry spark plugs, etc. gets 30 MPG on level ground at a steady 55 MPH. Your particular LS400 probably gets more like 27 MPG at 55 MPH because a number of maintenance items need attention or have been neglected over the years such as the air filter, oxygen sensor, throttle plate, distributor caps and rotors, etc. Expensive K&N filters and synthetic oils not only fail to increase gas mileage (by more than a trivial amount), they also distract car owners from spending time and money on the maintenance items that are causing the cars to get only approx. 27 MPG or so at 55 MPH instead of 30 MPG. So the savvy LS400 owner that's getting 27 MPG @ 55 MPH will spend time and money on certain maintenance items using genuine Toyota parts and procedures that will get the car back up to at least 29 MPG, while the "mechanic in a can" oriented LS400 owner will buy a K&N and synthetic oil and get 27.5 MPG instead of 27.0 MPG.

Compressor and magnetic clutch life can be greatly extended by observing a few rules: 1) Run the AC system at least 5 minutes at least once a week throughout the year, not just in summer. 2) If several days have elapsed since the last time you ran the AC system, turn it on only if the car is at idling speed, not while the engine is spinning fast such as on the freeway. Inside the compressor there are pistons and cylinders just the inside of a car engine and compressor oil drains off critical parts after several days of non operation.

No residual pressure = no residual refrigerant was in the system. There were recent threads on recharging the '91 LS400 and they answer the questions you have posed.

Here are the $23.00 Denso universal oxygen sensors the Ebay seller claims will even work on even the 2003 model Lexus's: http://tinyurl.com/juubn

R134a

The heater should still work in winter even if the air conditioning system is empty of refrigerant. In fact, the air conditioning system (compressor) is designed to stay shut off if the outdoor temperature is below 32 degrees F. The purpose of the engine fan is to PULL cool air from the front of the car through the radiator in order to cool the coolant inside the radiator. The engine fan has nothing to do with the heater.

We discussed this in detail for you two years ago: http://us.lexusownersclub.com/forums/index...opic=10381&st=0

Would you want to buy the cheapest spark plug available? Probably not, because you probably realize how important the spark plugs are for top engine performance and fuel economy. Same thing applies to oxygen sensors.

Use of dyes is not recommended by Toyota because Toyota considers dyes to be a system contaminant that could degrade long term system reliability / durability. Toyota has always recommended use of an electronic refrigerant leak detector or (in the old days) a halide torch leak detector. Dealers and most AC shops have an electronic leak detector. An easy way to prevent refrigerant leaks from ever developing is to simply run the AC system for at least 30 seconds and preferably for 5 minutes or more once every week or two throughout the year, including the winter months.

I'd pump the system down as low as you can with the vacuum pump. Then charge R12 VAPOR through the low side only, with the can held upright (and engine shut off). Like mehullica says, "you will get in some charge due to the vacuum in the system and pressure of the charge cans." In addition, you can help this process along by immersing the can in a container of water that is about 110 degrees F. The hot water creates enough pressure in the cans to force R12 vapor into the system. (water temps of 120 degrees F or above could cause the cans to explode !!) Once you have enough R12 vapor (approx. 1-2 cans) in the system while the engine is shut off , that will be enough to create sufficient system pressure to get the compressor to start up and run (if you turn the engine on). From that point on, set the interior AC controls for maximum cooling with the engine idling and let the a/c compressor pull in the rest of the charge out of the cans of R12 at about 2000 rpm. Charge enough to make the bubbles in the sight glass on the receiver-drier to dissappear. As mehullica says, make sure you have added compressor oil to the system. On caveat: you should also replace the receiver-drier since the system likely become contaminated with moisture when it was totally empty of refrigerant (when old compressor was removed). Replacement driers come with the sight glass blacked out with paint. So if you replace the receiver-drier you can't use the sight glass anymore and will have to look up the refrigerant capacity for your model year ES250 and add only that amount. The factory manual also tells you how much new compressor oil is needed when you change the compressor and receiver-drier. Still another caveat: if the original compressor suffered internal burn out due to loss of compressor oil, the resulting metal shards and debris could have circulated around and contaminated the system and possibly hasten destruction of the new compressor and the system expansion valve (the valve that meters refrigerant into the evaporator). But if just the magnetic clutch attached to the compressor seized / stopped working and burned up the rubber drive belt, then your old compressor itself really didn't burn up and cause any system contamination (because the magnetic clutch is an external device that has no contact with the refrigerant and compressor oil)

The valve clearances on some valves of the early 1990's V8 sometimes get out of adjustment. Overly loose valves will create a ticking noise in the engine, but the engine may still idle rock solid smooth. Overly tight valves may creat some engine vibration at idle. Engine power and fuel economy can be off 10% or more when several valves are substantially out of adjustment. Driving along time with valves that tick loundly can cause permanent mechanical impact damage to the affected valve lifters. Damaged lifters can be replaced, but the procedure requires camshaft removal.

Yep, from personal experience. Example: in the early 1990's the factory original spark plugs that were installed on some Toyotas came from the factory set at a gap of .041" - which is optimum for performance and fuel economy - even though the factory spec listed in the owners manual is .043". Now if you buy genuine Toyota replacement spark plugs for these same Toyota engines from a Toyota dealer, they will also come set to .041", But if you purchase them from an auto parts store they'll be set at .043" or ,044" resulting in less responsive engine performance.

I'd jack up the front end, remove the brake calipers (but take care not to depress the brake pedal with the calipers removed) and spin the wheels to listen for roughness and clicks. Also, grab each wheel and try to push it away from you and then pull it toward you to check for bearing slop and play. There should be virtually no detectable play. Yes, worn wheel bearings can click, contribute to steering wander and they definately increase road noise. However, my knowledge of worn wheel bearings is limited to conventional tapered roller type front wheel bearings. I think the LS has sealed ball bearing type front wheel bearings and I can only guess the symptoms of worn ball bearings would be similar to the tapered roller type. I also think the LS's front wheel bearings should be good for 300,000+ miles if the car is driven on smooth roads and never through serious floodwaters.

Try searching all the forums using "synthetic leaks" as your search words to read about the owners who succumbed to peer and advertizing pressure and switched to synthetic and then wished they hadn't because now they have oil leaks that would cost $1,000+ to fix.

KYB (short for Kayaba) is a Japanese company that has been an OEM supplier to Toyota for decades. When shopping for prices, consider getting quotes from discount Lexus dealers as well as wll as other sources. Example one owner said: "I've gotten good service and 30% off retail from Matt Molini of Lexus of Roseville:" Matt Molini Parts Associate Lexus of Roseville Phone: 916-783-9111 Fax: 916-677-8840 Email: mmolini@lexusofroseville.net www.lexusofroseville.com

If you buy from oxygensensors.com you 1. pay a little more than the $147.58 price a discount Toyota or Lexus dealer will charge for a front Denso sensor. 2. You pay another $100+ for a new rear sensor because oxygensensors.com says you need to replace both the front and rear sensors. But the rear sensor lasts twice as long as the front one and has no effect of fuel economy or emissions, therefore it does not need to be replaced until the car has mega odometer miles (up around 250,000+ miles) 3. You may not end up with a perfect fit Denso sensor that is exactly the same in every way, as the factory original sensor (exact same length pigtail wires, etc). 4. You may be lured into buying an inferior "universal" oxygen sensor or aftermarket brand like Walker (Walker recommends replacement of their sensors every 30,000 miles which doesn't say much for the quality !) Sparkplugs.com has these same shortcomings too.

Monitoring HC and CO emissions and fuel economy is a good way to gauge oxygen sensor performance. If your engine still generates CO & HC emissions in the single digits ( 0 - 9 ppm) and you havn't noticed any loss of fuel economy then your sensor is still likely working pretty good. If you plan on keeping the car along time and don't want to face future expenses like catalytic converter replacement then you need to do everything possible to minimize the amount of fuel the engine consumes and the amount of emissions it generates. The catalytic converter and EGR valve on one of my Toyotas is still going strong after 469,000 miles because I replaced the oxygen sensor before it wore out enough to trigger a check engine light. To replace the sensor you soak the mounting nuts overnight in penetrating oil and then use a six point socket or box wrench to loosen them. I slowly loosen a bit, spray penetrating oil, then tighten a bit, spray again and then loosen, etc. so as to not strip the threads. But on a 2001 California Lexus like yours, the mounting nuts and threads are probably not hardly corroded yet.

In the upper Midwest, ethanol gasoline has been on the market for many years and here in Calif. most gas stations started using ethanol in place of MTBE last year. It hasn't been causing any problems in Toyota / Lexus vehicles.

The gas mileage kings are the 2WD 4 cylinder Highlander and Rav4. They get about 28 MPG at 60-65 MPH vs 22 for the Sienna and 20 for the V6 4Runner.

The front oxygen sensor (one ahead of the cat converter) is the one that is constantly sending a signal to the Engine Control Module to adjust the fuel-air ratio for maximum fuel economy and lowest emissions. As the oxygen sensor ages, it gradually gets lazy resulting in slightly higher fuel consumption and slightly higher emissions. When it gets really lazy the check engine light will come on and by then your fuel economy could be off as much as 2 MPG. The rear sensor has no effect on fuel economy and lasts approx. twice as long so shouldn't need replacing until around 250,000 miles. The Toyota Highlander 3.0L V6 probably uses the same front oxygen sensor as the RX300 V6 http://www.1sttoyotaparts.com/partscat.html OXYGEN SENSOR, Highlander, 3.0L, Front 01-03 MSRP: $204.9 Sale price: $147.58 So if your local Roseville Lexus dealer (Matt Molini ? ) was willing to sell you the RX300 sensor for around $150-160 that would be a good deal considering that dealer cost is probably around $120.