red flags

yeah, i know the saying, "if you give a man a stethoscope he'll think he's dying", well i pulled out my scantool (autoenginuity) and found some odd readings and other things besides. If i'm just crying wolf, just tell me to sit down and shut up and I will gladly do so.

1. (edit, corrected CID values)
B1S1 O2 Sensor Voltage Readout: nice sinusoidal rhythm between .03 and 1
B1S2 O2 Sensor Fuel Trim: between -4 and 2
B1S1 O2 Sensor Voltage Readout: flat between .73 and .75
B1S2 O2 Sensor Fuel Trim: 99.06 (never changes??)

does that look right? maybe I just dont know what i talking about


2.
If i turn on the air, the rpms dive and the engine sputters for a few seconds before revving itself way up and down. idle 620, drop to 200, shoot to 1800, back to idle. Only happens when the air is on though and never happened before.

3.
Position 5 on the fan speed selector sometimes works sometimes doesn't, new problem today.

4.
theres a light out behind my tach, i know there are guides online probably, but I thought id ask for tips or how tos first. Specifically, what kind of bulbs go back there and how many, I might as well replace 'em all.


other than that, no DTC's or any other erratic readings besides the B1S2 Fuel Trim static at 295mw out of 300mw.


thanks again in advance

To the best of my knowledge the post cat., B2S2, does not control fuel trim.
That is the job of the pre-cat. sensors. The post cat. data stream should be fairly flat @ idle if the cat. is functioning properly.
What ever is responsible for monitoring and regulating engine load readings is probably responsible for your variation in RPM's.
Also if you have B2S2, where is the info for B2S1 ? And also for B1S2 ?

Do you have the 4.2 or the 5.3 L ?

4.2 is one bank naturally, the flat readings on#2 are ok as mentioned., there would be a code set if any of these readings were outside operating parameters, '73-.75 is not good for a warmed up engine above idle. The blower relay/ resistor is bad, mounted on the blower case behind the glovebox.

Ok, figured I better close this thread before I become one of those people I hate who never post their answers...

1. I don't know what I'm talking about
2. TB cleaning fixed it up
3. Replaced the relay, good as new
4. Putting this off for summer, def. not spending 300 for a new cluster.

Thanks all, and sorry for the long time to reply, school is nuts right now.