# Clearing SES light



## Sphinx (Sep 25, 2004)

What's the best method to clear the ses light? I tried the method of turning the key to the on position and then dancing on the pedals at prescribed intervals. It isnt' working for me. Any ideas?


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## chimmike (Oct 17, 2002)

unplug the battery for 10 mins.


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## Sphinx (Sep 25, 2004)

chimmike said:


> unplug the battery for 10 mins.



This is getting frustrating!! I unplugged the battery overnight (by removing the negative terminal) and the light is still there and the codes are still the same.

Just to be sure that I'm not crazy, here's what happened. I replaced the downstream O2 sensor. There are two O2 sensors. ONe on the top of the exhaust manifold and one on the bottom. The second one I thought was supposed to be aft of the cat, but it seems to me to be between the manifold and the cat. Is there a third sensor out there and did I pull the wrong one???

The car is a 2000 G20.


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## no1see2me (Oct 1, 2004)

Sphinx said:


> This is getting frustrating!! I unplugged the battery overnight (by removing the negative terminal) and the light is still there and the codes are still the same.
> 
> Just to be sure that I'm not crazy, here's what happened. I replaced the downstream O2 sensor. There are two O2 sensors. ONe on the top of the exhaust manifold and one on the bottom. The second one I thought was supposed to be aft of the cat, but it seems to me to be between the manifold and the cat. Is there a third sensor out there and did I pull the wrong one???
> 
> The car is a 2000 G20.


You need a OBD II Reader, that will tell you the codes and will allow you to clear them, however if you bought after market sensors from like autozone or something, those codes will not go away. Their is a difference with those sensors even if they are made by the same manufacture. It's one of those "You must get from the dealer" items.

hope this helps.


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## chimmike (Oct 17, 2002)

if the codes are the same, there's still a problem!!!!!!

how does the car run and what is the code ???

could be a simple leak somewhere in the exhaust system making the O2 sensor show lean.


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## ukrainian102 (Nov 10, 2004)

Go to Autozone and get them to read the codes. Cheaper than at the dealer. :fluffy:


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## Sphinx (Sep 25, 2004)

ukrainian102 said:


> Go to Autozone and get them to read the codes. Cheaper than at the dealer. :fluffy:



I had already read the codes. I have a basic code reader that I got from Harbor Freight. The codes were 138 & 139 which is the rear o2 sensor. Clearing the codes is what I'm having trouble with now that the part was replaced.


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## chimmike (Oct 17, 2002)

then the problem isn't fixed, like I said.

check/replace the exhaust manifold gaskets and make sure there are no leaks in teh exhaust around that area.


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## Sphinx (Sep 25, 2004)

chimmike said:


> then the problem isn't fixed, like I said.
> 
> check/replace the exhaust manifold gaskets and make sure there are no leaks in teh exhaust around that area.



Solved! Not sure how, but solved.

I went to plug my cheap Harbor Freight OBD2 reader and walked back into the garage. When I came back out two minutes later, the light was out. Yippie!! And that was three or four days ago. Car has been driving without a hitch. $51 for the sensor + my sweat equity = $400 from the dealer (who wanted $180 just for the sensor).

BTW, the old sensor was stamped with a Bosch logo. And the new one was a Bosch. 

Thanks for everyone's tips!!


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