97 Epedition Check Engine Light

Ok People I Need Your Help
My Engine Light Came On About 6 Months Ago, I Dont Drive This Vehicle Much Well Last Week My Truck Would Not Start
Thanks To This Web Site After Following All Of You All Advice
Did Replace Iac Valve ....it Did Start...thanks

But Now The Engine Light Stll There One Time My Friend Took The Truck To A Dealer And According To The Dealer An Oxygen
Sensor Is Bad ?????? It Has Like Four ?????? What Can I Do
Should I Go To A Delaer And Get It Fix......

Please post the exact code number. There are many variables to the "O2 syndrome"

Thats The Problem I Dont Have The Code???

Go to Autozone or Advance or a parts chain house. They will read the codes for you. Write the code numbers down and post back.

Ok People I Need Your Help
My Engine Light Came On About 6 Months Ago, I Dont Drive This Vehicle Much Well Last Week My Truck Would Not Start
Thanks To This Web Site After Following All Of You All Advice
Did Replace Iac Valve ....it Did Start...thanks

But Now The Engine Light Stll There One Time My Friend Took The Truck To A Dealer And According To The Dealer An Oxygen
Sensor Is Bad ?????? It Has Like Four ?????? What Can I Do
Should I Go To A Delaer And Get It Fix......

I have the same issue so I went out and bought a scanner turns out my EGR valve needs changing. So I would recommend buying a OBD( ON BOARD DIAGNOSTIC) scanner to first see what the problem is and go from there.

I have a 98 Expedition and my check engine light came on. I went to Advance Auto to get the free diagnostic test. It came up as needing a erg valve. I got that fixed as well as the pcv valve and hose. Even after those repairs my check engine light is still on. I took it back to Advance Auto for another reading now I have codes P0172 and P0174 (System too lean Bank 1) what does that mean, and how to fix it.