'91 Sunbird 3.1 - Engine Light, No Code

Nov 16, 2003 4 Replies

I do a lot of highway driving, and lately noticed that sometimes the Service Engine Soon light will come on if I decelerate down from, say, 75 MPH. It stays on for anywhere from several seconds to maybe a minute or to.



I checked for codes, but none are stored... just does the 12,12,12, pause,



12,12,12.

Idles fine, runs fine in city traffic.



One thing though, when I'm on the highway, sometimes it will stumble, or miss, very slightly, and only for, like, a split second. Does this intermittenly while driving down the highway. Like I said though, very slightly, but noticable to me.



Any suggestions? Thanks, Mark.


Just a guess and a hint: if original, the plug wires are now 12 years old. Whether good or bad, if they are indeed original, don't you thnk that car deserves "unclogging its arteries"? HTH, s

Mark wrote: I do a lot of highway driving,

It may be an oxygen sensor issue. Strange that it is not setting any codes.

Dennis

Plugs and wires are new from Feb this year. I like to replace the wires every couple of years. I have plans to replace the plugs though, just in case one is bad.

Thanks, Mark.

I have a spare O2 sensor from a '87 2.8L Chev I used to drive. It should be good, I didn't have any problems with the Engine when I dumped the car.

Thanks, Mark.

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