Service Engine Soon light question

[LTJGWorth]

I have a 1992 Safari 2WD V6 with 175000 miles and the check engine light will come on after I have driven it for a while. It doesn't always come on and it never comes on when I first start it up or let it sit and idle. The van runs pretty good, but shifts a little sluggish. Could it be an O2 sensor? Thanks for the help.

[Marcus Krueger]

get the error code. any mech should have areader.
don't replace parts unnessarily.

[bpnsd]

yes it could be an o2 sensor or any one of another hundred or so possibilities.

[LTJGWorth]

Sorry I didn't post on this sooner. Turned out to be my VSS (Vehicle Speed Sensor). I already knew that it didn't work because when I replaced the tranny, I didn't replace the VSS correctly. Thanks for the help.