My check engine light came on for awhile I knew right a way it was the O2 censor, anyways after a while it goes off so I figured I would go get my emmisions test done, I call the guy to set it up and he tells me that theres no point in testing it till I change the O2, I tell him cel went off, he says doesnt matter the computer saves the info till its fixed, so I scan it again and sure enough it throws the O2 code. My question is if I change the censor will the computer see this and clear itself or do I have to clear it. Do I use the OBD erase button or pull the fuse.

 

You can clear it by unhooking the battery for 15 minutes or so if I remember correctly.

Rob

 

Yep, 15 mins or so with no power and the ECU should reset with no codes. BTW it will also reset all the fuel trims memory so the truck may run slightly different until it relearns the adjustments.

 

You can also just clear it with your OBD2 tool. Same thing as disconnecting the battery but a lot faster.

 

you can just pull the 15A EFI fuse..30seconds or so should do the trick...that way you do not have to reset the radio,clock,ect...

 

Sometimes it takes longer than 30 sec, there must be a capacitor somewhere that holds a charge for short battery disconnects. Like maybe long enough to switch out batteries or something.

 

obd 2 computers have capacitors in them

you can disconnect both cables from the battery and hold them together for about 30 seconds, that will usually drain the capacitors

 

So I deffinately have to clear the computer then.

 

it would be a good idea

 

Clearing the code through the OBD2 removes the code from the computer. No need to pull the battery and reset everything. If you have an OBD2 reader use it to clear the code. A lot easier.