Dirty Oxygen sensors

[IronOutlaw]

My grandpa has a 94 vette that he doesnt drive much at all. Has 70000 miles in it and is like a brand new car. He usually drives it on back roads under 45 miles an hour putting around.

My uncle bought a 93 vette and wanted to ride up to the mountains to try the car out. Well, he was scared of the car and drove 27 miles an hour for the first 45 minutes.

After this everytime my grandpa would stop the car would go dead. It ran perfect cruising but couldnt hold an idle. A check engine light came on when it was running bad but he hasnt gotten it scanned yet, couldnt find anyone with an obd1 scanner.

So, when they gets on the open roads my grandpa "blows the soot out of it" and drives very spiritedly for a few miles and the car begins to run perfect and the light goes off. He read in the owners manual that after sitting in traffic the oxygen sensors can get dirty and the engine needs to be held at 2000 rpms for 10 minutes to clean them off and this will cause the car to idle rough.

Well, anyone hear of oxygen sensors getting dirty or could he have another problem?

(Im exhausted and going to bed so this post may not make much sense.)

[Firebat]

I would suspect the Idle Air Control on the throttle body is dirty. Take it out and clean it will throttle body cleaner spray.

Could be other things but start with the simply stuff first. Check out the IAC and check fuel pressure.

[LT1RUNNER]

Well, anyone hear of oxygen sensors getting dirty or could he have another problem?

(Im exhausted and going to bed so this post may not make much sense.)

Sure they do. Well they actually get clogged with soot from unburned gas.

[Spartan7]

Get the code scanned first. I have no idea what OBD connector a 93 Vette has, but the code will be stored in the PCM memory (considering you haven't disconnected the battery or pulled the PCM fuse).