in leu of switching over from fmu to uberdata/dsm 450s... I went ahead and changed over my intank to a walbro 255 pump last weekend. I was driving around today and got a cel code 45-lean/rich. Is this common?

My setup is t3/t4@4psi of boost in a B18B, 12:1 fmu & inline fuel pump. I wasn't beating on it or anything when it occurred. I had primed the pump several times before startup. I was driving it for two or so days before this code. I didn't smell anything unusual when this occured.

any help would be great.

 

It's getting more fuel now with the new pump, running rich. The O2 sensor is probably covered in soot, hence code 45. Clean the sensor and see if the code comes back. If it does, you'll probably have to change the sensor. It may be that no matter what you do with an FMU and that pump that it will run pig rich under boost, so ultimately it will end up being a tuning issue.

 

so if i say away from boost until i get everything setup, I should be okay right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scartail &raquo;</TD></TR><TR><TD CLASS="quote">so if i say away from boost until i get everything setup, I should be okay right?</TD></TR></TABLE>

Hard to say, that pump creates higher pressure than your stock pump, and the FMU creates a restriction on the return line even when not in boost, so your static fuel pressure is probably a bit higher than it should be, so a rich condition may be present even when not in boost, or even while idling. The ecu should be able to compensate for it in closed loop, but not with a contaminated sensor, that would be the first thing I'd address, then move on from there.

 

I'll give it a shot... Thanks for the info.