Check Engine Light Is On

[billccc]

i have a ES250 with 130k mile, recently the check engine light is on, specially at first 3-5 mile on highway, it will go off when you drive longer , so i can't show my technician what is going on, anyone has same experience or idea what could be.

many thanks.

[steviej]

you can trip TE1 and E1 with a paper clip and count the number of times the CEL flashes to determine you codes.

here are the instructions.

www.troublecodes.net/lexus/

let us know what you find, then we can help you better.

steviej

[billccc]

you can trip TE1 and E1 with a paper clip and count the number of times the CEL flashes to determine you codes.

here are the instructions.

www.troublecodes.net/lexus/

let us know what you find, then we can help you better.

steviej

←

i got the instruction from the website, thanks steviej,

where is DLC located, and what different between DLC1, DLC2?

[Toysrme]

There are several DLC's located throghout the car. They all check for different things. They all have TE1 and E1 so it won't matter which one you do.

[billccc]

i have a ES250 with 130k mile, recently the check engine light is on, specially at first 3-5 mile on highway, it will go off when you drive longer , so i can't show my technician what is going on, anyone has same experience or idea what could be.

many thanks.

←

hi steviej, i read the code as your instruction, it is 71, i haven't figure out what is that mean, but now the light is off again, :P, thank you very much.

[billccc]

There are several DLC's located throghout the car. They all check for different things. They all have TE1 and E1 so it won't matter which one you do.

←

i found one under the hood, it is small box, but it is labeled clear, i got code, thanks

[billccc]

you can trip TE1 and E1 with a paper clip and count the number of times the CEL flashes to determine you codes.

here are the instructions.

www.troublecodes.net/lexus/

let us know what you find, then we can help you better.

steviej

←

hi steviej, i read the code as your instruction, it is 71, i haven't figure out what is that mean, but now the light is off again, , thank you very much.

[Lexusfreak]

So what does the code mean?

[Toysrme]

Ya you live in California ROTFLMAO!

EGR gas temperature is too low.

Take the EGR valve off and clean it by hand, check the vacuum hoses, and vacuum switching valve. There may, or may not be any electronics on it, I would doubt it but...

If it has a post cat o2 sensor, I would check it too. Boy it sounds wierd saying that.. 90-91 2vz-fe's only had 1 o2 sensor normally, 87+ didn't have any LoL!

[billccc]

Ya you live in California ROTFLMAO!

.

Take the EGR valve off and clean it by hand, check the vacuum hoses, and vacuum switching valve. There may, or may not be any electronics on it, I would doubt it but...

If it has a post cat o2 sensor, I would check it too. Boy it sounds wierd saying that.. 90-91 2vz-fe's only had 1 o2 sensor normally, 87+ didn't have any LoL!

←

toysrme, thanks for replying.

where is the EGR valve, how to clean it , if i don't clean it, any damge will happen?

please explain a little bit more about "EGR gas temperature is too low"

[Toysrme]

Well, it'll be impossible to pass CA emessions testing, cause the CEL is lit, and there's probably a 50-50 split on being able to pass a sniffer test. it wuold probably depend on how good the cat still is, and the main o2 sensor.

Modern cars recycle exhaust back into the intake. Because the exhaust gas has less oxygen in it (It's been through combustion) it makes the effective air/fuel mixture richer than normally possible, without actually having to add more fuel & change the mixture.

This lowers combustion chamber temperature.

Because of the combustion chamber is lower, there are less nitrogen oxides that form in the exhaust gas.

Scroll down to 2vz-fe.

You don't want to test it (Unless you want to, and or have the equipment). You just want to start out by taking the EGR valve itself off, and cleaning it by hand.

After you put it back on, you want to pull the EFI fuse out (box nearest the battery) for a second and replace it. That will clear the trouble code & stored data. If it doesn't come back, problem fixed; if it comes back, well I promise at least you helped a little bit! LoL!

Let us know how it goes, or ask anything you need.

[billccc]

Well, it'll be impossible to pass CA emessions testing, cause the CEL is lit, and there's probably a 50-50 split on being able to pass a sniffer test. it wuold probably depend on how good the cat still is, and the main o2 sensor.

Modern cars recycle exhaust back into the intake. Because the exhaust gas has less oxygen in it (It's been through combustion) it makes the effective air/fuel mixture richer than normally possible, without actually having to add more fuel & change the mixture.

This lowers combustion chamber temperature.

Because of the combustion chamber is lower, there are less nitrogen oxides that form in the exhaust gas.

Scroll down to 2vz-fe.

You don't want to test it (Unless you want to, and or have the equipment). You just want to start out by taking the EGR valve itself off, and cleaning it by hand.

After you put it back on, you want to pull the EFI fuse out (box nearest the battery) for a second and replace it. That will clear the trouble code & stored data. If it doesn't come back, problem fixed; if it comes back, well I promise at least you helped a little bit! LoL!

Let us know how it goes, or ask anything you need.

←

thank you so much for your information.

i checked the code yesterday and also cleared the code after check, the check light is off. but i din't do anything except read the code. so i am not sure whether should i still need to clean the EGR valve,

maybe the previous owner forgot clear the code.

i will try to clean the EGR valve anyway.

one more question is "the exhaust gas" must be hot than air, why it can lower the combustion chamber when it was conducted back to the chamber?

[mscott]

'cause you got little O2 to react with = less energy in chemical reaction = less heat = less work on cylinder head... as opposed to regular "air" + fuel...

[SKperformance]

Doesn't the egr work by returning the exhuast gases which contain Co2 which is used to stiffle burn temps which lower the overall exhaust temp to reduce the Nox production at the end of the burn cycle?

"Smaller effective displacement means less fire, and less heat and thus lower temperatures, thereby controlling NOx emissions"

[Toysrme]

To burn you need fuel and an oxidizer. Oxygen is the only oxidizer present. Less oxygen = less bang; less bang = the less heat.

You can reduce nox easily by simply richening the air/fuel mixture. This lowers combustions temps. The trade-off is that less of the mixture does not burn completely, and HC/CO is increased.

You can also reduce nox by retarding ignition timing. This can be horrible for emessions tho! The more you !Removed! the timing, the more of the mixiture burns in the manifolds, and the less in the combustion chamber. General emessions sky-rocket, and power output is lowered.

If you're very astute, you notice that the upper intake manifold / throttlebody itself has coolant running to it for no other reason that routing coolant. What the actual point of routing coolant there is to cool the EGR pipe that runs under the intake manifold! (EGR flows in a middle chamber, coolant flows down one side and back out the other)

[mburnickas]

how do you clean and EGR then?

[SKperformance]

The coolant flow is to heat the intake chamber air upon cold start not for the EGR.

[Toysrme]

That's secondary for -50*F operation.

[94es300_turbo]

yea i have the same problem....it has been on ever since 94000miles and i now have 97400miles.... and when i drive for long periods of time it goes off.......and then later itcomesback on.........any help.....