Cleaning Egr Vacuum Modulator

[Bill O']

I have a '90 LS-400 WITH 303,000 miles on it and am getting an intermittant Check Engine EGR code 71.

I am beginning the troubleshooting process with the easy (and inexpensive) fixes. At the Lexls site there is a tutorial on how to inspect and clean the filter on the EGR Vacuum Modulator. It looks simple but the trouble is I can't seem to get the top of the unit off.

I used a small screwdriver and then the tip of a knife to try and pry the top off but all I wound up doing was peeling the sticker back.

Am I prying in the right place (right at the seam between the sticker and the very top of the plastic top) or is the lid seam further down the body of the unit?

I also considered that being such an old part that there is no top to remove to get to the filter.

The two part numbers on the sticker are: 25870-500010 and 139000-2880. Is's made by Denso.

Thanks

[vcv10guy]

Unless it is completely different from my engine. I believe the top of the egr that covers the filter is popped off at the side. The place where you are trying to open it is not the place. The whole plastic top needs to be popped off where the hoses meet the cap. Hopefully this helps you. On a side note, 303,000 miles is quite an achievement.

[RFeldes]

I agree with vcv10guy, you may want to use a" little" dwd40 around the edges and let it sit overnight and try again. Proud of your mileage also.

[92Lex]

Imagine that the modulator is a soda bottle. The cap that you are trying to pop off is the cap of the soda bottle...it doesn't screw out and you want a sip, so you're going to have to pry the cap off with a screwdriver. Take a screwdriver put it under the lower rim of the cap and "flip" it up.

[Bill O']

Thanks for pointing me in the right direction. I'll give it a try tomorrow and let you know how I make out. As regards the 303,000 miles, I'm only responsible for logging 3,000 of them. I just bought the car from a Lawyer friend of mine who commuted from Pasadena to Manhattan Beach, CA Mon-Fri. It was garaged on both ends and dealer serviced for 14 years. Everybody says with proper maintenance these babies are good for 500,000 miles so I figure it's just broken in and will be good for 197,000 more miles of happy motoring!

[Bill O']

Well I got the modulator cleaned, (filter was VERY dirty) and no check engine light so far. As a bonus, the car now idles at 650 the way it's supposed to after warm up. It used to idle at 1200 in N or P all the time. Is the modulator related in some way to idle control?

Thanks again.