# EGR What is it? What Does it do? Why does the light go on for a few days, then off, then on **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** nissan, altima\ **Created:** [August 26, 2019, 1:46am UTC](https://community.cartalk.com/t/egr-what-is-it-what-does-it-do-why-does-the-light-go-on-for-a-few-days-then-off-then-on/147512 "2019-08-26T01:46:54Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Kama\_Linden](https://avatars.discourse-cdn.com/v4/letter/k/278dde/32.png) [@Kama\_Linden](https://community.cartalk.com/u/Kama_Linden)\ **Post date:** [August 26, 2019, 1:46am UTC](https://community.cartalk.com/t/egr-what-is-it-what-does-it-do-why-does-the-light-go-on-for-a-few-days-then-off-then-on/147512/1 "2019-08-26T01:46:54Z")
Hi. I have a Nissan Altima, 2001. My SERVICE ENGINE SOON light will go on for a few days, then off, then on again…the code is “EGR”. Apparently, my mechanic said this happened back in Oct. He just had to clean out the engine a bit. He had to also “fiddle with it” so it would pass inspection back in April. Starting at the end of July, the light went on, and it was EGR. I called him…he said “it won’t harm the engine” but he would need a day to a day and a half to go in there to see what would trigger it. Sure enough, it likes to go on when I go back to NY, and go off when I am in NJ. It’s staying on now. Went off briefly this moring. Waiting to get in to see him, as he is very popular, and does not overcharge. However, this will be the last nice weekend at the Jersey Shore. I have driven like 2000 miles since this started. Thoughts? Thanks Kama ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [August 26, 2019, 1:53am UTC](https://community.cartalk.com/t/egr-what-is-it-what-does-it-do-why-does-the-light-go-on-for-a-few-days-then-off-then-on/147512/2 "2019-08-26T01:53:28Z")
Do you know how many EGR codes there are? If you don’t know the code, it’s anybody’s guess. Tester ---
**Author:** ![Kama\_Linden](https://avatars.discourse-cdn.com/v4/letter/k/278dde/32.png) [@Kama\_Linden](https://community.cartalk.com/u/Kama_Linden)\ **Post date:** [September 17, 2019, 12:53am UTC](https://community.cartalk.com/t/egr-what-is-it-what-does-it-do-why-does-the-light-go-on-for-a-few-days-then-off-then-on/147512/3 "2019-09-17T00:53:39Z")
So I have been told. Well, Nissie was crushed by a Dodge Ram, so I now have a different car. Thanks ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [September 17, 2019, 2:18am UTC](https://community.cartalk.com/t/egr-what-is-it-what-does-it-do-why-does-the-light-go-on-for-a-few-days-then-off-then-on/147512/4 "2019-09-17T02:18:03Z")
> [@Kama\_Linden](#): > > Well, Nissie was crushed by a Dodge Ram, so I now have a different car. That sucks, Hope you are OK ---
**Author:** ![Kama\_Linden](https://avatars.discourse-cdn.com/v4/letter/k/278dde/32.png) [@Kama\_Linden](https://community.cartalk.com/u/Kama_Linden)\ **Post date:** [September 17, 2019, 2:20am UTC](https://community.cartalk.com/t/egr-what-is-it-what-does-it-do-why-does-the-light-go-on-for-a-few-days-then-off-then-on/147512/5 "2019-09-17T02:20:11Z")
16 years! Last day of vacation Just wanted to see the sunset one more time. Was waiting at a yield sign. The DODGE RAM TRUCK with PA plates went, or so I thought. I rolled out and BAM! “You have insurance, right?” and drove off! ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [September 17, 2019, 3:32am UTC](https://community.cartalk.com/t/egr-what-is-it-what-does-it-do-why-does-the-light-go-on-for-a-few-days-then-off-then-on/147512/6 "2019-09-17T03:32:42Z")
I expect you don’t need to know what the EGR is used for at this point. If still interested out of curiosity, post back.