ibuddler

Hi,

I'm new to the forum. I've got a 98 ES300 since day one. It's 144k right now but I still love it so much. However, recently CEL came on with the code P0401. I changed the ERG valve and reset the CEL. It came on again with the same code after a couple days.

I read from this post https://www.clublexus.com/forums/es3...nt-how-to.html

It's for 92-96 ES300. However, for 97+ ES300, there's no EGR Vacuum Modulator. I'm wondering if it's been replace by VSV or Vacuum control valve? Should I replace these too? Can anyone post a picture and show me the location and what they look like? Thank you.

Also I want to know how bad it will be if I leave the CEL on? Does EGR flow insufficient affect the gas mileage? I want to keep it for another 15 years or reach 300k.

Hayk

iTrader: (1)

Have you inspected the EGR tube that goes down to the exhaust? It could have gotten plugged up with carbon deposits. EGR helps with fuel economy at cruising speeds.

ibuddler

Thank you for the reply. No. But how can I check the tube? Just blow or suck it? I don't have tools and I'm not a very handy man.

For the second part, as long as I'm not using cruise control, it shall not affect at all. Correct?

Hayk

iTrader: (1)

Cruising speeds, meaning holding a steady pace on the highway or anything above 40mph. You can read the Wiki article about EGR to get a better understanding.

mitmaks

Make sure all of your vacuum lines are connected and are not obstructed. Mainly line that goes to the egr valve. I would check to see if your egr valve is working right and trace back all the lines that are connected to it.

ibuddler

Well, I've unplugged the tube connects to EGR last Friday and it looks pretty clean. Then I cleaned the CEL and I've driven over 50 miles during the weekend and no CEL light. However, this morning it came on again. I've already replaced the EGR valve with the EGR sensor on it. What's my next step? How can I check my EGR is working?

GS4_Fiend

iTrader: (22)

First and foremost, you do not change the EGR without testing it first. You need a vacuum pump and apply vacuum to the EGR, if it works, the engine will stumble. If not, the EGR passages are clogged. If EGR works, and CEL is still on, you must test the Modulator and the VSV. Remove the vacuum line that connects to the EGR and rev the engine, do you feel vacuum from the vacuum line?

ibuddler

Thank you for your steps. For the EGR testing, can I just remove the tube connects to EGR and suck the EGR while my engine is on?

For the second part, what does "rev the engine" mean? Should I put the engine to reverse while I'm testing it?

Thanks.

Hayk

iTrader: (1)

Rev = raise RPMs

mitmaks

ibuddler

Last night I can confirm that my EGR is working properly. I'll try the second test tonight and let you know. Thanks.

I'll watch the Youtube when I get home.

GS4_Fiend

iTrader: (22)

You can safely isolate the EGR valve and the EGR passages. The culprit is either the modulator or the EGR VSV. But most likely it's the modulator.

ibuddler

Thank you. Where is the modulator on a 98 ES? What does it look like?

mitmaks

http://www.ebay.com/itm/Dorman-EGR-Vacuum-Modulator-Fits-Toyota-Camry-Avalon-Celica-RAV4-Solara-/230944854455?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3AES300&hash=item35c562d1b7&vxp=mtr

ibuddler

OK. I did the second test last night.

I can feel the vacuum when I give the pressure to the gas pedal. The vacuum can't last constantly although my RPM still remains at 3k. It more like an instant thing. If I slowly give the pressure to the pedal, I don't feel anything.

Does that sound normal?

Btw, where is the modulator on a 98? I know where it is on a 96 but I think they replaced the modulator with VSV on the later model. Can someone post an actual picture?