Trane won't stay lit, no flame code

[firehazard]

I watch my Trane and the flame comes on but shuts off after a few seconds. This may happen a few times in a row then will give "2 blink" code, indicating it does not recognize the flame. I can see what looks like a thermo couple that may reside in the path of the flame before the fan. Could it be that this little gem might be going bad? If so, can a regular schmoe(sic) buy this part at Walmart? Kidding, the fans come on, the flame starts up fine. It will stay lit if I let it "rest" for a while, so I assume that whatever circuit that senses the flame has become intermittent. Any advice? Thanks in advance.

[hvacwiz]

Remove the flame sensor and clean it with fine sandpaper or steel wool.

[firehazard]

Thanks for the quick reply. Is the sensor located by itself between the fan and burner assembly on what looks like the section of sheet metal just above the burners? With 2 yellow wires attached? 2 hex head screws holding what looks like a small black/metal rectacular face plate with some part numbers on it?

[HayZee518]

a flamerod detector consists of one wire, the body of the bracket forms the other part. two wires indicate a millivolt generator. it is a tube that sits inside or slightly outside the main pilot or burner flame. if it doesn't detect the pilot flame, the pilot will not open.

[mike n]

Yes clean the flame sensor it will be obvious when you look at it many times the act of taking it apart will reground it and your problem will be solved