1999 4x4 Chevy tahoe o2 sensors

[buddha95023]

Need help in with pn # for all 4 o2 sensors ,,upstream and downstream

My hoe has been a money pit ..lol have replaced intake ,head gasket ,spider assembly,distributer,plugs,wires,cam sensor,about to do o2 sensors, to pass smog....

 

[IronMan4Real]

Find a legit honest master technician. The amount you invest in proper diagnostics is far better than guessing at parts. A friend is a master tech,He gets paid $100 to diagnose this stuff. He says he spends whatever time to diagnose whether its 5 min or 5 hours and stands behind his work 100% or offers to fix it free, he makes absolute sure he is correct before calling the customer to repair as well he is an emissions tester. He says I have to be right...no room for error.
Having worked in garages and dealerships...an honest diagnosis is worth is weight in gold vs paying for unneccesary repairs.
Best of luck

 

[lesterl]

Why do you want all 4 sensors, the downstream have nothing to do with the emissions other than if the cats are good or bad.

If you are getting some bad readings, look into why you are reading rich/ lean to begin with (leaking FPR/ vacume leak to name 2...)....

 

[laredo1307]

If you've replaced all this stuff and it's still running bad, then I doubt the O2 sensors are the problem. I've heard of people chasing the same issues and it turns out there was a crack in one of the heads that was causing everything.

 

[IronMan4Real]

Mine was bank 1 sensor 2. Post cat drivers side 02. Checked voltage to be sure and it was. Replaced it and voila.