Jim Grant's Tech Tips
'97 Dodge Intrepid, Check Engine Light
constant problems with the check engine light coming on. When it came
on again, I checked the oil and it was a low. I filled it back up and
the light did not go off. I disconnected the battery for a few minutes
to clear the computer. When I turned the car back on, the light was still
on. So I did the on/off thing to get the malfunction indicator lamp codes.
The code that came up was 21. Do you know what this is? I was unable to
find any info on the Internet.
code your vehicle's computer is reporting (#21) is for an oxygen (O2)
sensor problem. The only problem with that information is there are about
18, the last time I counted, possible failure types. What makes it more
difficult is your vehicle's engine configuration could have 4 O2 sensors.
(Any of which could be failing for one of 4 to 5 reasons each, depending
on which sensor.) You'll have to have the dealer or area garage ask the
computer for more details on why the check engine warning light is on.