So I recently got a 2010 Ranger sport with a 4.0 in it and it has been pulling the P2196 O2 sensor biased/stuck rich bank 1 Sensor 1 code. It constantly runs rough and is low on power and has bad mpg. I’ve tried cleaning the mass air flow, replaced both upstream O2 sensors, Checked fuel pressure, and did my best to try and locate any vacuum leaks. Also swapped all the spark plugs, wires, and ignition coil. Bank 2 had extremely carbon fouled plugs but bank 1 wasn’t as bad. If anyone has any insight on other possible causes or experience with this issue help would be appreciated!

 

Welcome to the forum

Rich code means computer is having to reduce injector open time on that bank, bank 1 which is passenger side of engine
So not a vacuum leak or MAF sensor issue, or O2 sensor issue, but 2010 Ranger would need new O2 sensors regardless, they only last 12 years

The 6 fuel injectors are connected to the Fuel Rail, its a fuel tube that runs around the lower intake, on the passenger side near the firewall at the end of the fuel rail is the pulse damper, has a vacuum hose attached to it, can be on driver side as well, looks like a small can with vacuum hose

Remove that vacuum hose and check it for gasoline, shouldn't be any, if there is thats the problem, raw fuel is being sucked in to the engine, replace damper

Fuel pressure..............should be 60psi running
above 30psi engine off
Fuel pump is capable of 80+ PSI if the in tank regulator fails

If its dropping to 0 psi you could have leaking injectors, its a LONG SHOT but possible

 

So after searching the engine bay for the FPD I couldn’t find it at all. Do you happen to know where the vacuum line on it runs to so I can possibly trace it back? Or maybe a diagram or picture so I know where it should be located?

 

Should look like this: https://i.ebayimg.com/thumbs/images/...Dur/s-l300.jpg

Shown here at the end of a fuel rail: https://www.autozone.com/znetrgs/rep...3f80204fa5.gif

 

So after doing further digging it’s not there at all. So I’m not sure what happened for it to get taken off but I’ll have to try and find a new one and a vacuum hose

 

I would just leave it as is, the pint was to fin why it was running rich and if there is no pulse damper then it can't be leaking into a vacuum hose that's not there, lol