phishtaco
Cincinnati
The CEL came on in my wife's 4runner and of course I drive it and it turns off. Can they still pull the codes if the light has turned off?
CEL ??? on 4runner
- Thread starter phishtaco
- Start date
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Yes
Similar if not the same procedure for pulling codes on an 80. the computer stores everything until it is cleared
Similar if not the same procedure for pulling codes on an 80. the computer stores everything until it is cleared
Not necessarily. A EGR not opening or opening at the wrong time may throw an O2 code.
When the EGR opens it changes the reading at the O2. The ECM expects that change. When it doesn't happen then its out of expected range at the O2 so it will throw an O2 code.
A mis fire on the older trucks may also throw a O2 code for the same reason. The fuel mixture is out of range if a cylinder doesn't fire. Same with a lean injector. If the ECM can't adjust the mixture to range then it will throw and O2. This is also VERY dangerous situation. In the case of an injector running lean it may run the other cylinders rich and hide the problem till it burns a valve (Guess how I know that).
Diagnostics before money. Don't become the typical "Guess and spend" repair person the dealers have. Trouble codes are recommendations of what to inspect not the definite problem. If you read the trouble shooting guide in the FSM it will have several things to check for that code.
Test the EGR. Pull the plugs and see if any look drastically different. Meter out the plug wires, Check timing....Etc. Eliminate all other possibilities before spending money.
