What about O2 sensors? I'm not sure if they have been replaced or if they're malfunctioning or if they're ok what... Is that something I should invest in?

 

dtc13 will hold the system in closed loop so it will be in a rich mod. that will be hard on the 02 s and the plugs. this is what i have, the one thing i dont know is if the test are different for your yr.

 

hi, I think I might have a similar problem with my cats/o2 sensors...
is there a way to check the o2 sensors without replacing them?
and can I unplug a cat without replacing it? they're somewhat expensive...
I'm pulling 18s when I should be getting 24s.

 

Me too!

 

it most likely is muliple issues. test the evap system (sticky at the top of the lt1 sectin), check the fuel pressure regulator (pull the vacumm hose of and check to see if theres fuel in it), test the 02 sensors, found this and im to lazy to tipe it out,lol.

If you don't have the scanner, use a digital volt meter and test the output of each O2 sensor. You should see the same, rapidly changing voltage the scanner would see. If the voltage rapidly varies between ~.2 and .8v, it is obviously "crossing" the .450 threshold. Using a scanner just adds to the warm fuzzy that the wiring from the O2 to the ECM is good.

 

Thanks for that info! I'll look into that