Originally Posted by runarenis
im sry im new to this forum and i cant find where to post this. im haveing trouble with my grandfathers van he has fought cancer and has left him very weak so he has trouble working on his ram ( its the van version but i didnt know where else to turn) he has 3 codes on in it and i dont know where to start with them. they are P0141, P0138 And P0720 O2 Sensor heater bank 1 sensor 2 circuit malf, o2 circuit high volts bank 1 sensor 2, and output speed sensor circuit malf. now i just dont know if these are just the sensors shot or if its in the wireing. any help is much apreciated and again im sry that this is in the wrong area plz forgive me
Welcome to the forum.
I read this post and it seems that you're van may be in need of a O2 sensor replacement or two. Since those are OBD 2 then the vehicle will have two O2 sensors one pre-cat which is used to measure the emissions to assure the fuel mixture is correct and the other is for the post-cat sensor which was instituted on the dodge vans back in 1996 and been there up to the end of manufacture 2003. The post-cat sensor probably isn't bad, many times if the cat isn't working properly then the ECM will throw a code for that sensor, the best way to eliminate the cat is to have the truck hooked up to an emissions tester or if you have a DRB2 or MT2500 scan tool which can run diagnostic testing of your dreams.
Another thing is to just replace the sensor and see if that makes any difference. The the code is for the sensor heater, the pre-cat O2 sensor as I know has a heater on it to pre-heat the sensor, O2 sensors don't give accurate readings until the sensor has reached temperature generally 600F, so the heater element heats the sensor and keeps it nice and warm to give accurate readings.
The last code is a speed sensor code, if the speed sensor wasn't connected then the vehicle wouldn't be able to start without that signal but it's possible that you just have a loose wire or the sensor is broken, again you need to get a diagnostics tool. Scan tools just read codes, diagnostics tools can read the codes and then use the onboard software to run diagnostics tests. Anyways I too would need more information about the van such as exactly which year, what motor. Things like that, there where changes made to the vans mainly in software over there final years.