97 GMC Sierra SLT 5.7 123K, multiple problems
 

Hey Guys,

Im having a few issues with my 97, first the dash get really hot when the heater is on, and there is a weird sound from under the dash when I start the truck. Also the defrost stays on all the time....Maybe the vent motors/valves?

Second, when its cold, on the first cold start of the day the motor is making a rattling noise, I think it has done this before but this year its a little more noticeable. Sounds like a dry start from the bottom of the motor....

Third, My o2 sensor has gone out, 2 bank 2nd sensor, should I change all four?

Re: 97 GMC Sierra SLT 5.7 123K, multiple problems
 

Tell us about the things they inspect (or not) for in OK.

Re: 97 GMC Sierra SLT 5.7 123K, multiple problems
 

Nothing, no inspections...but if your caught without cats you get a fine...

Re: 97 GMC Sierra SLT 5.7 123K, multiple problems
 

So get simulators for the back O2s and be done with those.

$40 dual channel I used them for years until I had them programmed out by Pcmforless

Vent issues will require pulling off the front of the dash.

Noises require listening and perhaps gauges. Use of screwdrivers to the ear can help.