Flex fuel pump finally died on me, so I swapped in a Walbro 450 in the stock bucket. After a multiple stage, lengthy swap (thanks in large part to Racetronix lack of quality control), I fired it up last night and CEL came on

Pulled the following codes at O'Reillys for my 2003 Tahoe 5.3 flex fuel running on E85 right now:
P0169 - incorrect fuel composition
P0452 - fuel tank pressure sensor
P0446 - Evap, vent system performance
P0463 - fuel level sensor, gauge reads empty (I think I messed this up squeezing the assembly back into the tank)

I didn't touch the fuel composition sensor nor remove or mess with the fuel tank pressure sensor. No idea about the vent system performance.

Has anyone run into these problems after a fuel pump swap? Any ideas for what needs to be fixed? I plan to replace the fuel level sender, but can I tune the rest out or are they caused by problems I need to address?

 

smash some wires?

 

That would be my guess as well.

 

Now that I think about it, I unbolted and moved the evap canister a bit to make room to work under there. Didn't disconnect anything intentionally, but may have jostled something loose

 

mess up any of the quick disconnects?
gas filler tube all the way on correctly? . . . and the over fill tube?

try clearing the codes first?

 

that's what I'd do, clear them and recheck!

 

Good idea, I'll do that tomorrow. I did test the pump with the module out of the tank, which may have caused some of them... hopefully

 

Don't think so, and the filler and vent tubes and on and snugged down, but I'll give them a twist just to be sure they're on there.

Nope, that's probably where I should have started to see what pops back up.

 

tested the pump by cycling the key on?

 

Yeah, hooked up the harnesses and fuel lines, then checked for pressure at the rail by priming the pump. Wanted to make sure everything worked before I put it all back together.