Question: O2 Sensor Change

[C4_Lover]

Had the O2 sensors changed out in my 94 vert. Car ran great, no lights on dash. Got back from a 100 mile trip today and noticed alot of carbon buildup on the tips of my Magnaflow exhaust. (Seemed more than usual) Is this normal or possibly the EGR valve starting to go?

Thanks for any info.

 

[Schrade]

More carbon than usual? How do you gauge the amount?

If you got no SES lights, I wouldn't worry too much about it. Just out of curiosity tho', what was your mileage at cruise? My '94 at 70 did just over 29, and at 54, it would hold just under 33 MPG's (32.9/turtle gears in back - 2.59).