Engine Light Codes: No Symptoms

From : mel

Q: few days ago engine light came on 96 4cyl dakota and i accessed codes. no codes came up. started engine and light went out. today engine light came on and again flashed for codes. came up with 12 and 21. 12 = memory standby power lost and 21 = oxygen sensor. truck runs without problems. any ideas on whats happening with those codes and why no symptoms dakota has 82k and have not changed any sensors...thanks. .

Replies:

From : budd cochrantom lawrence

yeah its big enough but does it come with cupholders vbg do you think i would need oversize tires on my truck if i dropped a single cylinder version of it in budd terra wrote budd cochran wrote thats one that id like to see the torque curve for. it just about has to be as flat as a kansas pool table. must see - http//www.bath.ac.uk/ccsshb/12cyl/ i think max could climb a connecting rod of this one. and fit an extension ladder inside a cylinder. in the pic of the crank for the 10-cylinder version note the steps by each crank throw that lead down into the crankcase .

From : tom lawrence

and again flashed for codes. came up with 12 and 21. 12 = memory standby power lost and 21 = oxygen sensor. truck runs without problems. any ideas on whats happening with those codes and why no symptoms there are symptoms - you just cant perceive them. the computer is saying the signal from the oxygen sensor isnt flipping back and forth - its either reporting always lean or always rich. in either case your engine isnt operating as efficiently as it could. most likely at the detection of this the computer will revert back to its stored fuel maps instead of relying on the o2 sensor not sure about that but thats the logical operation. youre probably running on the rich side which means your fuel economy is going to be down and the plugs will foul quicker. depending on your state you probably wont pass an emissions inspection. now it could be just a bad o2 sensor. it could be an intake gasket leak thats leaning out the a/f mixture and the computer cant compensate for it. it could be several other things. an o2 sensor isnt that expensive so if you want to gamble and just change it out it wouldnt be the end of the world. otherwise you should have it checked out by a shop. .

From : fmb

i have a 93 almost the same thing except no check engine light came on. i pulled the codes cause the milage dumped from 17 to 9 mpg. it was the o2 sensor. replaced and back to normal. fmb only one b in fmb and again flashed for codes. came up with 12 and 21. 12 = memory standby power lost and 21 = oxygen sensor. truck runs without problems. any ideas on whats happening with those codes and why no symptoms there are symptoms - you just cant perceive them. the computer is saying the signal from the oxygen sensor isnt flipping back and forth - its either reporting always lean or always rich. in either case your engine isnt operating as efficiently as it could. most likely at the detection of this the computer will revert back to its stored fuel maps instead of relying on the o2 sensor not sure about that but thats the logical operation. youre probably running on the rich side which means your fuel economy is going to be down and the plugs will foul quicker. depending on your state you probably wont pass an emissions inspection. now it could be just a bad o2 sensor. it could be an intake gasket leak thats leaning out the a/f mixture and the computer cant compensate for it. it could be several other things. an o2 sensor isnt that expensive so if you want to gamble and just change it out it wouldnt be the end of the world. otherwise you should have it checked out by a shop. .

From : orland

is it difficult to change the sensor and arent there more than one thanks for the info. and again flashed for codes. came up with 12 and 21. 12 = memory standby power lost and 21 = oxygen sensor. truck runs without problems. any ideas on whats happening with those codes and why no symptoms there are symptoms - you just cant perceive them. the computer is saying the signal from the oxygen sensor isnt flipping back and forth - its either reporting always lean or always rich. in either case your engine isnt operating as efficiently as it could. most likely at the detection of this the computer will revert back to its stored fuel maps instead of relying on the o2 sensor not sure about that but thats the logical operation. youre probably running on the rich side which means your fuel economy is going to be down and the plugs will foul quicker. depending on your state you probably wont pass an emissions inspection. now it could be just a bad o2 sensor. it could be an intake gasket leak thats leaning out the a/f mixture and the computer cant compensate for it. it could be several other things. an o2 sensor isnt that expensive so if you want to gamble and just change it out it wouldnt be the end of the world. otherwise you should have it checked out by a shop. .

From : fmb

is it difficult to change the sensor and arent there more than one thanks snip only one on the 83 cant speak for others. as far as changing it out follow these well-worn steps 1. go buy the part 2. unplug the pigtail 3. unscrew the sensor 4. compare pigtails 5. try to see if your new pigtail will streach that far 6. go back to the store for the right sensor with the longer pigtail 7. screw in the sensor 8. connect the pigtail 9. clear your puter .

From : gunbunny31

or............... save yourself the trip and pull the o2 from the truck take it with you to the dealership. stay away from autozone and most other jobbers with a o2 sensor unless you like to re-do the joe several times the part # is stamped on the steel collar of the o2 sensor all of the chrysler o2s are. the parts guy will know what to get you from there. and yes i am calling out the aftermarket when it comes to a o2 sensor. i have seen enough fail and had to re-do the job just to make some one happy. i dont do that any more. i wound up living with the problem. no more .

From : orland

problem i called dodge for the part and they wanted to know which one i wanted upstream or downstream. flashing the codes with the on/off sequence doesnt distinguish one o2 from the other. btw sensor is $80 at dodge and $68 at carquest. not worth buying cheaper one... or............... save yourself the trip and pull the o2 from the truck take it with you to the dealership. stay away from autozone and most other jobbers with a o2 sensor unless you like to re-do the joe several times the part # is stamped on the steel collar of the o2 sensor all of the chrysler o2s are. the parts guy will know what to get you from there. and yes i am calling out the aftermarket when it comes to a o2 sensor. i have seen enough fail and had to re-do the job just to make some one happy. i dont do that any more. i wound up living with the problem. no more .