so, i have been staring at this check engine code for the last couple of months. i dont have the exact code on me right now, but i will get it on my way home (i pass right by an auto zone) it is an o2 sensor code. now anyone who drives a dakota knows about the terrible downstream o2 sensor issue we have and how they are prone to fail. unfortunately for me, o2 sensors aren't too cheap now a days, and i dont feel like buying one if that isnt my problem. so after all that, here is my question. what is the easiest way to tell if it is the cat or the o2 sensor? anyone want to take a stab? (or let me know where i can get my hands on a real cheap o2 sensor! )

 

Not sure how to tell which is bad, maybe a smog place would have some tips.

I am not sure if they are the same for all motors in that year, but try this link, cheapest I have seen. http://cgi.ebay.com/ebaymotors/DODGE...30593897QQrdZ1

 

just to let everyone know, i found a bosch downstream o2 sensor for $55 shipped at autopartswarehouse.com

 

well before you go plunkin down hard earned bux on a new sensor... you could go get some CRC electronic parts cleaner at the auto parts store, yank out the o2's and clean them. spray it liberaly into the openings and dont be stingy... I've cleaned about a dozen sensors so far and all of them worked excellent after the cleaning. on my wifes old '02 dak, hers was throwing a cat in-effecinecy code, cleaned the sensor, reset the pcm and it never came back.

as for telling if a cat is good or not, have someone behind the wheel rev it to 2000~2200 rpms to heat up the cats and while they are reving it, use a temp gun and measure the input & output temps of the cat... normal is the output's are hotter than the inputs. anything else and the cat is bad.