Dgoude

Dirty throttle body probably won't make any difference for WOT (wide open throttle) performance. It is more of a problem with erratic idling. The throttle plate doesn't close properly (tightly) due to carbon buildup and the leakage of air by the plate counteracts the IACV modulation of throttle speed.

If you have WOT performance issues it might be blocked fuel filter, weak fuel pump, dirty air filter, dirty injectors, MAF, ignition, or coolant temp sensor. I would think all of these are more likely candidates to full throttle response than a dirty throttle valve.

All this said it isn't a bad idea to scrub the TB every 50-70k miles so you don't get poor idle problems. Especially as the engine gets older and there is more cylinder blow by. Just don't be disappointed if it doesn't help WOT performance though.

Thanks guys. The car has 176k miles on it and I've never cleaned it before. So worst case scenario I have a clean throttle body! Just hoping all of the gaskets hold up during the change!

Thanks again for the advice. Really appreciate it!

Ok... found the post. Not for an ES but still great... http://us.lexusownersclub.com/forums/index.php?showtopic=30723

But here's another question. To clean my throttle body is it necessary to take the entire thing off, or can I just disconnect the air intake valve, spray some carb cleaner in there and go? Or do I need to go through the entire process? I'm just trying to get a little pep back into my car's step. Don't have any idling problems or anything like that.

Any advice/suggestions would be great.

Thanks!

There used to be a post on here that gave step by step instructions and pictures on how to clean the throttle body for a 99 ES300. I finally have time to do this tomorrow and I can't find that post anymore. Does anyone happen to know the link for that post?

Thanks!

I had this same problem. I went to Auto Zone and had them run a diagnostic on it while the check engine light was on. It came back as a few different possibilities. Long story short, I ended up replacing the Mass Air Flow sensor and it eliminated the problem. You might be able to see if this is what you need to do by performing a simple test. Disconnect the battery for a minute to let the check engine light reset. When you start the car the light should have gone away. Get on a stretch of road where you can try to accelerate quickly. If you push the gas hard and after a moment the check engine and VSC lights come on together you have your answer. MAF it is.

Hope that helps!

Is there a post on here that gives the diy instructions for that? Thanks guys!

Hello everyone. I have a '99 ES300 with 165k miles on it. Still runs great but as the years go by I'm getting slower and slower. I have replaced the spark plugs and the Mass Air Flow Sensor. I change the oil every 3k miles with high mileage oil and filter. But I'm wondering what other things I can do to tune her up and make her respond a little better. I know I'll never have the engine of a new car again, but anything you can offer that would help her purr a little better would be appreciated.

I have noticed that it gets worse in warmer weather if that helps you offer any other advice.

Thanks everyone!

My 99 ES300 is leaking oil from somewhere and I can find it so I'm looking for help in where to look. I've checked the pan plug and I've checked around the spark plugs but I can't find it. It's not leaking much at all, maybe a few drips every day. But when I stop and idle for more than 30 seconds I can smell it really heavy in the car. So it's burning off somewhere.

I am a novice at best in car repairs. I've done rotors, brakes, and replaced my spark plugs. So please help me figure out where to look to see what the culprit on the oil leak is.

Thanks in advance!

I would recommend taking it to a independant shop. Lexus dealer at best will overcharge you. The code you have can be read by any good professional scanner. My personel scanner is a snap on mt2500, gennisiss also makes a good scanner, unfortunatly both are too expensive for weekend mechanics. With a professional scanners you can read the code, and see engine information. Such as engine coolant temp (reads out in deg) lets you know in a second if the computer is reading the correct temp, (note quite often the instrument pannel temp gauge, and the computer temp gauge are totaly independent, one sensor could be working fine, the other could be dead). You could also read O2 sensor switching. You mentioned that you had to replace the injector o'rings, by any chance was that on the same bank that is now reading lean? If so did you lubricate the lower oring before inserting it into the intake manifold? Could you possibly have nicked a oring? Possibly you might have accidently caused a vac leak.

This was actually happening long before I had the incident with the injectors. I'm pretty sure I did everything correctly when putting those back together.

So if I took it someplace like Christian Brothers they might be able to tell me exactly what the problem is instead of the ambiguous "lean" and 5 different possibilities that I got from Auto Zone?

I really appreciate your help more than you know!

I looked up the code, alldata has the same code description, except for the missfire. So start by checking all vac hoses for cracking (especially the intake, between the throttle body and airflow sensor). Do you have any idea when the last time the fuel filter was changed? They also mentioned clogged injector and engine coolant sensor. It takes speciallized tools to check the injector, but you could test the temp sensor with a DVM. You could also just shotgun the temp sensor if it is not too expensive. The last thing they mention is the airflow meter itself, but that is not something you could test without a good scanner.

As far as I know the fuel filter hasn't been changed since I stopped going to Lexus for the services about 4 years ago. I've just started within the last year working on the car myself. Changed the brake pads and rotors, changed the spark plugs, and by accident had to change all of the "o" rings on the front fuel injectors. So bottom line is the only thing I know how to do on the list of things that you mentioned above is do a cursory check of the hoses. Did that today when I changed the oil and didn't see any visible cracks when checking from the top.

So I guess I should take it to Lexus, have them diagnose the problem and then fix it myself if I can?

Where can I find a good replacement steering wheel for my 99 ES300? I've looked on Ebay and they have them from time to time, but wanted to know if anyone here has dealt with a place that is trustworthy.

Thanks

agreed , lean is too vague.

Sorry I didn't put year. I have a 99 ES300. Oddly enough the Check Engine, VSC and VSC OFF lights all come on at the same time. (More details about this below the update)

****UPDATE****

Went to Auto Zone and here is the Code that they came back with...

Troubleshooting Code: PO171

OEM Brand: Domestic

Definition - Fuel trim bank one condition

Explanation - The powertrain control module uses the oxygen sensor to calculate air/fuel ratio of the engine. The computer has recognized a rich or lean condition on one engine bank only.

Probably causes...

1. If bank one and two codes set together suspect fuel pressure or MAF (Mass Air Flow) Sensor

2. Oxygen sensor defective

3. Ignition misfire - repair

4. Fuel Injector problem

****

Maybe this will help explain a little more so someone can help me diagnose correctly the first try!

Before I replaced the battery terminals I had a bad connection that made me have to go and jiggle the terminals every once and a while to get them to connect and get juice flowing again. Every time that happened it reset the Check Engine light. So when I would get on the road again and hit the interstate and accel quickly, the first thing that would happen is my VSC and VSC OFF lights would come on. Then I would reach my destination and turn the car off. The next time I drove it, without fail, if I had to accelerate again, the Check Engine light comes on with the VSC and VSC OFF lights.

Can someone tell me the best way to get the wires out of the battery terminal? The factory has them stuck so hard I can't figure out what to get in there to pry the teeth loose.

Also, I got this type of terminal http://www.partsamerica.com/ProductDetail....396&PTSet=A for my batter and I'm not 100% positive where I put both of the wires from the positive side. There is one wire that goes into the part that you clamp down on, but on the original terminal, there is another wire that goes on top. Any help would be greatly appreciated.

I would just cut the wires off the old terminals. As far as the second wire for the positive termianl, use a crimp on terminal and hook it to one of the two clamp bolts. I would recomend soldering the terminal to insure that you have a good connection.

Thanks... that's what I did and it worked out. There was one snag though and it was that the positive side cable, once cut, wasn't long enough to reach the terminal that I purchased. So I went to Auto Zone and got a cable extender and attached it and all was fine. No more "no starts" for me!

Thanks for your help!

Went to Advanced Auto yesterday and had them run a diagnostics check. It showed up as "lean" which the guy said he's been confused on. Some people say it's an air leak, some people say it's the 02 sensors and some say it just needs a tune up. Anyone have any more info on that?

Can someone tell me the best way to get the wires out of the battery terminal? The factory has them stuck so hard I can't figure out what to get in there to pry the teeth loose.

Also, I got this type of terminal http://www.partsamerica.com/ProductDetail....396&PTSet=A for my batter and I'm not 100% positive where I put both of the wires from the positive side. There is one wire that goes into the part that you clamp down on, but on the original terminal, there is another wire that goes on top. Any help would be greatly appreciated.

What tools do I need to reach the three rear spark plugs in a 99 ES300? Is there a flex ratchet that would work for this? I was using a 1/2" rathcet with a 7" extender for the front that fit perfectly but that's way too big for the back. Any suggestions?

I GOT IT!!!!!

I was missing one gasket on each injector. Just got her purring like new. Now that I know where the back spark plugs actually are I think I'll wait a week or two before attempting. Anyone have recommended tools to get in that tight space? Geesh!

Oh man, that long silver tube that you pulled off is the fuel rail! It sounds like you took out the front three injectors. Is it the tube in the attached picture? When looking at the picture, the front three coil-pack/spark-plug locations are across the bottom of the picture. The front bank fuel rail is circled in blue. You should be able to just reseat each of the three injectors by pushing them all back down into their holes (both in the fuel rail and intake manifold) and retightening the retaining bolts... just make sure you didn't slice any of the o-rings in the process, for they are sensitive. Then make sure the banjo bolt is nicely aligned and tight at the end of the fuel rail.

The spark plugs are further back in the engine (closer to the firewall) behind that aluminum intake plenum. A few inches back you should find the coil packs or the wires leading down the spark plug cavity (depending on what model of ES300 you have; some have individual coil packs all around, others share the front coil packs with wire take-offs to the rear bank of cylinders). The way these transverse mounted 1MZ-FE engines are designed, the front three plugs are cake to access and replace, but the rears are a buggar. It just takes time and patience and they can be replaced without issue.

Hey man. You nailed it. That's exactly what I did. I went back to the auto parts store and picked up new o rings, but when I put everything back in place it is still leaking pretty bad out of the first and third injector. Is there something else that I need to do with the fuel rail alignment? Am I tightening it too much?I'm giving it everything I've got. I replaced the o rings inside the fuel rail then replaced the o rings on the tops of the first and third injectors. I also replaced the o rights that go right below the top one and then the large one at the bottom where it fits back into the engine. It is leaking really bad from the top (where they connect to the fuel rail). Am I going to need to get new injectors or am I just not lining it up the right way?

Thanks for the reply!

Have any pictures of the area?

I don't but I found out today that it is the fuel injectors for the front plugs. Oops! I went and got some new gaskets for it but when I put it back on it's still leaking pretty bad. I'm going after it again tomorrow. If anyone has some good tips on how to get that to stop leaking it would be greatly appreciated!

Thanks!

Hey guys,

I'm trying to change the spark plugs in my car. I got the front ones done and thought the back ones were right behind them. I undid all of the tubing and unscrewed this long silver piece that has the characters "2C" and "L" on it. Can anyone tell me what that is? When I unplugged it it hissed and spit out some gas. Now I've tried to put it back on and it is leaking gas horribly when I start the car. I think all I need are three new gaskets for the piece, but I'm not 100% sure. Can anyone help me?

Hey guys,

I'm trying to change the spark plugs in my car. I got the front ones done and thought the back ones were right behind them. I undid all of the tubing and unscrewed this long silver piece that has the characters "2C" and "L" on it. Can anyone tell me what that is? When I unplugged it it hissed and spit out some gas. Now I've tried to put it back on and it is leaking gas horribly when I start the car. I think all I need are three new gaskets for the piece, but I'm not 100% sure. Can anyone help me?

I have a 99 ES 300. When I first purchased it I had to take it into the dealer 3 or 4 times because the VSC and VSC OFF lights kept coming on. They eventually replaced the car's computer and that remedied things... until now. About three months ago the VSC and VSC off lights started coming back on. But now they only come on when I try to accelerate quickly. The acceleration is very slow and sluggish and as soon about 5 - 8 seconds after I push the gas hard, while in the middle of accelerating, the VSC and VSC off lights come on. And just recently the Check Engine light has been coming on with them. If just the VSC and VSC OFF lights come on all I have to do is turn the car of and restart it and the lights go off. If the Check Engine light comes on with the other two lights, I have to unhook the battery and then they all go away until I accel again. Can someone PLEASE tell me what I need to replace or fix here?

I have a '99 ES 300 with 135K miles on it. I had problems when I bought the car in '02 with 23k miles on it with the VSC and VSC Off lights coming on spontaneously. I took it to the dealership 5 times and they finally decided to replace the on board computer. This solved the problem until recently.

The last few months the problem has returned but this time with other symptoms. Sometimes if I punch the gas, whether just starting off or hitting it hard to accelerate, the engine bogs down for a few seconds and then catches. But recently when I've been getting onto the interstate and have had to accel quickly the VSC and VSC Off lights have come on (sometimes with the Check Engine Light and sometimes not) and the car is very sluggish. It was sporadic at first and now it is every time I have to really hit the gas. If the Check Engine light comes on with the VSC and VSC Off lights I have to disconnect the battery and it all resets and goes back to normal until the next time. If the Check Engine light doesn't come on along with the others, all I have to do is shut off the engine and it doesn't come back on again until I have to accel quickly again.

I am not a mechanic by any means but do like to DIY and have the Haynes manual. I've changed my rotors before and spark plugs (in a previous car) so I'm not afraid to get my hands dirty if it's something I can do myself. Can anyone help here?

Thanks,

Dgoude

Dgoude@gmail.com

I have a '99 ES 300 with 135K miles on it. I had problems when I bought the car in '02 with 23k miles on it with the VSC and VSC Off lights coming on spontaneously. I took it to the dealership 5 times and they finally decided to replace the on board computer. This solved the problem until recently.

The last few months the problem has returned but this time with other symptoms. Sometimes if I punch the gas, whether just starting off or hitting it hard to accelerate, the engine bogs down for a few seconds and then catches. But recently when I've been getting onto the interstate and have had to accel quickly the VSC and VSC Off lights have come on (sometimes with the Check Engine Light and sometimes not) and the car is very sluggish. It was sporadic at first and now it is every time I have to really hit the gas. If the Check Engine light comes on with the VSC and VSC Off lights I have to disconnect the battery and it all resets and goes back to normal until the next time. If the Check Engine light doesn't come on along with the others, all I have to do is shut off the engine and it doesn't come back on again until I have to accel quickly again.

I am not a mechanic by any means but do like to DIY and have the Haynes manual. I've changed my rotors before and spark plugs (in a previous car) so I'm not afraid to get my hands dirty if it's something I can do myself. Can anyone help here?

Thanks,

Dgoude

I have a '99 ES 300 with 135K miles on it. I had problems when I bought the car in '02 with 23k miles on it with the VSC and VSC Off lights coming on spontaneously. I took it to the dealership 5 times and they finally decided to replace the on board computer. This solved the problem until recently.

The last few months the problem has returned but this time with other symptoms. Sometimes if I punch the gas, whether just starting off or hitting it hard to accelerate, the engine bogs down for a few seconds and then catches. But recently when I've been getting onto the interstate and have had to accel quickly the VSC and VSC Off lights have come on (sometimes with the Check Engine Light and sometimes not) and the car is very sluggish. It was sporadic at first and now it is every time I have to really hit the gas. If the Check Engine light comes on with the VSC and VSC Off lights I have to disconnect the battery and it all resets and goes back to normal until the next time. If the Check Engine light doesn't come on along with the others, all I have to do is shut off the engine and it doesn't come back on again until I have to accel quickly again.

I am not a mechanic by any means but do like to DIY and have the Haynes manual. I've changed my rotors before and spark plugs (in a previous car) so I'm not afraid to get my hands dirty if it's something I can do myself. Can anyone help here?

Thanks,

Dgoude