Hey I am new to the forum, but i came here to see if anyone could help me out. I have a 2001 Ram with a 318 in it. It is running extremely rich to the point its blowing black smoke out the exhaust. I know it isnt burning oil n that it has to be running rich. All of a sudden it started to miss a little n got a drastic drop in mpg's. Im lost n dont know where to start to look with this thing. If anyone has any idea what my problem could be i would appritiate it...

 

I would suspect the upstream O2 sensor as this helps determine how much fuel to dump.

Check your plenum as well.

 

I do have a check engine light on n when i had it check it said that the O2 sensor was reading lean..

 

Itr is reading lean because it is bad. And the PCM is dumping fuel because it thinks it is running lean. Without a functioning O2 sensor, the PCM has no way of knowing what is actually going on, so it will dump more fuel as fast as it can. bet mileage sucks...doesn't it? Replace the O2 (disconnect battery when doing so) and I bet the problem clears up and mileage gets better!

 

Hey thanks alot...when u said about the o2 sensor it just hit me...cant believe i didnt figure that out sooner

 

No problem. Sometimes the best way to see a problem is to bounce it off someone else...then it all comes together!

Hope that solves the issue. Be careful the brandd O2 sensor you get. I have not changed mine on my Ram, but I use Denso on my Yota. Someone will chime in on what works best on these trucks. I have seen where some are not good to use.

 

NTK or Denso are good. Bosch is bad.

 

Stay away from the Bosch 02.