My daughter owns a 2000 Dakota. The check engine light recently
came on and the vehicle began running very rough. Took it to a
local dealer and they pulled up a code of 171. They then advised
her to change the rear oxygen sensor and the spark plugs. She had
both done and the results are exactly the same. Still runs
rough. Has anyone had any similar problems and if so, what did
you find out?

 

Toolguy,</P>


Just fixed the Engine Light problem on my 1999 Dakota. I checked all the fluids and only found the coolant was a little low, this didn't help. I had run out about 3/4 of the last gas fillup when the light came on, don't know why but I bought a bottle of STP gas treatment $.99, filled up the tank and on the way home the truck jercked like it lost fuel and then ran great, oh the truck was running good when the light came on. I disconnected the battery when I got home , reconnected, started the truck and all is well. Hope this works for you.</P>

 

Toolguy, what size engine is in the Dakota ?</P>


</P>


Big Paw, Sometimes by disconnecting the battery cable, it is only a temporary fix. When the ECU cycles again, it may come back on. I am not saying it will happen but be aware it may come on.</P>

 

My light came on too. My trans was shifting wrong. I pulled the code off of it and had to replace the speed sensor on the tranz. It runs alot better now.

 

Tool Guy,
You did not indicate what engine you have, but one of our 2001 V6, we had numerous run ins with the check engine light. Here is what was found:
It appears this may be true with all new cars, if the gas cap is not tight it can cause the light to come one (this has something to do with the evap system). After I convinced the service guy that we do tighting the gas cap, and 3 more trips to the dealer, they found small pin hole in the lines that relate back to the evap. system. It worked great for about 6 months, then it came back. So theyreplaced the vaccum canster.
Then, the dealer found the motor was "hurt" said it was a bad #5 cylinder. Put in a new long block.
About 7000 miles later, the problem was back.
They then found the new motor had a leaking head gasket.
To date this truck has got 40,000 miles on it. We have another 2001 that was built the same day, same plant, same equipment and only had one problem with the inside dome light.
I hope this helps you looking for your problem?
</P>

 

My dad had the "not on tight enough" gas cap cause his light to come on.

After a check engine problem gets fixed it could take up to 100 key on offs before the light goes out, so disconnect the battery for 5 minutes and reconnect it. If the problem is fixed the check engine light will stay off, if it is not the light will come on again after a day or two, maybe sooner or longer. <img border="0" src=smileys/smiley2.gif border="0">

 

Be aware the "not tight enough gas cap" engine light will come on if your fueling while your engine runs. Happens alot around here due to being so cold outside.</P>


My wifes 03 Neon had a pin hole in the filler tube, up by the cap. Dealer smoked the system 3 times, always telling me the wife didnt have the cap on tight. On the 4th trip in, I told the dealer to get it right or I was doing a lemon law. Thats when they finnaly found the pin hole in the filler tube. After replacement, no check engine light in the last 10K miles.</P>

 

oops, I ment to respond to toolguys question:</P>


Here are the Oxy sensors trouble codes:</P>


130 Sensor heater relay problem
131 Oxygen sensor seems to be shorted out or broken
147 Oxygen sensor heater element not working properly (this device helps to
reduce emissions more quickly)
151 Oxygen sensor voltage problem - short circuit to ground?
152 Oxygen sensor voltage problem - short circuit to active 12V?
153 Oxygen sensor response too slow
154 Oxygen sensor does not show either a rich or lean condition - may need
replacement
155 Oxygen sensor heater element not working properly (this device helps to
reduce emissions more quickly)
157 Oxygen sensor voltage problem - short circuit to ground?
158 Oxygen sensor voltage problem - short circuit to active 12V?
159 Oxygen sensor response too slow
160 Oxygen sensor does not show either a rich or lean condition - may need
replacement
161 Oxygen sensor heater element not working properly (this device helps to
reduce emissions more quickly)
171 The oxygen sensor is saying that the system air/fuel mix is far too lean
(too much fuel is being added as a correction).
172 The oxygen sensor is saying that the system air/fuel mix is far too rich
(too much air is being added as a correction).
174 The oxygen sensor is saying that the system air/fuel mix is far too lean
(too much fuel is being added as a correction).
175 The oxygen sensor is saying that the system air/fuel mix is far too rich
(too much air is being added as a correction). </P>


You can check the codes yourself by doing one of 2 ways ( depends on model years )</P>


"on" being so the dash lights come on ,but the engine doesn't crank. </P>


Turn your key on while holding in your trip reset button..hold till a check system starts..
</P>


or</P>


turn the key on/off/on/off/on </P>


Jim</P>