A Little Guidance.....please???

[texchevy]

I posted this before and got no response. I just need a bit of guidance. I've taken my truck to Autozone and there are no code readings so now I'm really behind the 8-ball. Here is my previous posting:

I've got a 95 S10 and about a year ago the SES light started coming on only when I traveled on the highway. During that timeframe I had the fuel filter, the O2 sensor and the cat convert replaced on my truck within days of each other. It wasn't until the O2 sensor was replaced that the light stopped coming on.

My SES light started coming on again about a week ago under the same conditions as before (when driving on the highway). When it comes on it stays on but once I turn the truck off and start it again the light is off until I'm once again driving on the highway. I've just had the plugs changed but not the wires as of yet. The truck runs fine. Could the O2 sensor be gone again or is there more than one on the truck that was missed?

Any help would be appreciated!!

[Pewter'01SS]

I'm thinking that you have a sensor in the manifold and one or two in the pipe by your cat. convertor. Check the exhaust pipe in front of AND behind convertor. I know newer trucks usually have several O2 sensors. Check close to the tail pipe also.