gotaford 2000 ranger running rich on left bank got a black tailpipe and code default for left bank running rich .I can cut the check engine light by disconnecting battery and drive all day with light out and as soon as I turn it off.. then restart the light comes back on. could it be the o2 sensor giving the computer false read or maybe the MAS ? any ideas or thoughts?

 

get the code im gonna say 02 but since ur down there id replace both cause u know murphys law...

 

I know its an old thread but I don't wanna make a new one to ask the same question. I just replaced my egr valve and tube and now I'm running rich. Any ideas on what is causing this?

 

Post the PCM codes.
How do you know it's running rich ?

 

I got my check engine light checked and came up with three codes. I have them written down at home. I'll post them in an hour or two.

 

P0402 The ECM has detected too much flow on the EGR system
P0171 Fuel bank one condition
P0174 Fuel bank two condition

 

help? i think it might be my O2 sensors but i could use a second opinion.

 

make sure y didnt put ur EGR on backwards i know it sounds dumb but i see it all the time at work lol and make sure all ur lines are hooked up and u didnt miss one

 

How do you put it on backwards? There is only one way to put it on and the only lines that connect to it are the egr tube which is tight and the rubber hose on the top.