# 1998 Rav 4 Check Engine light

**URL:** <https://community.cartalk.com/t/1998-rav-4-check-engine-light/79874>\
**Category:** Maintenance/Repairs\
**Tags:** rav4, toyota\
**Created:** [June 15, 2013, 1:32am UTC](https://community.cartalk.com/t/1998-rav-4-check-engine-light/79874 "2013-06-15T01:32:22Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![guny180](https://avatars.discourse-cdn.com/v4/letter/g/90db22/32.png) [@guny180](https://community.cartalk.com/u/guny180)\
**Post date:** [June 15, 2013, 1:32am UTC](https://community.cartalk.com/t/1998-rav-4-check-engine-light/79874/1 "2013-06-15T01:32:22Z")

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I have a 1998 Toyota Rav 4 with apporximately 140,000 miles. When I fill the gas tank the check engine light comes on, the engine runs rough (like a misfire). Diagnostic code comes back a “lean mixture,bank 1”. When the tank reaches approximately 3/4 of a tank the light goes out and the engine runs smooth and fine. Then, when the tank reaches just belwo hal a tank the light once again comes on and starts running rough again. Have drained the tank, used dry gas, Startron to counter the ethonal etc. Nothing seems to work.

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**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:** [June 15, 2013, 4:15am UTC](https://community.cartalk.com/t/1998-rav-4-check-engine-light/79874/2 "2013-06-15T04:15:07Z")

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The ECM may be testing the Rav 4’s fuel tank evap system based on the fuel tank level. Often these tests are done at transitions to 3/4 full and/or 1/4 full. If one of the evap valves isn’t working correctly, like the purge valve, it could cause such a symptom. You might want to take a look at this link.

[http://www.agcoauto.com/content/news/p2\_articleid/294](http://www.agcoauto.com/content/news/p2_articleid/294)