I know I'm gonna need an ECU flash eventually, and prolly should now... However, I just installed Hallman Pro MBC.. Love it. Baught a Walbro 255lph fuel pump as well (haven't installed it yet). Can I run this pump in my 03 Evo, or am I going to need a flash/AFC/or some tuning device to make the AFR driveable. JW... I was guessing it might bring fuel pressure up for richen the car too much to make it drivable.

Any constructive input is appreciated. Thanks.

p.s.- will fuel-cut throw a CEL?

 

car will run extremely rich. You need to get a flash as soon as the install. You can still drive the car but will run like a pig!

 

I just installed mine about 2 weeks ago, and my car is running fine without a flash. Of course, I also have an intake, so my theory is, that I was running lean before the fuel pump (car was still running fine) and since the fuel pump makes you run a little rich, I figure it kind of evened itself out. Now before I get flamed, I am getting tuned this week, I know that this sort of guess work is no substitute for a tune. Every website I looked at when looking to purchase the pump said that tuning was recommended, but not required, you will just run a little richer.

My advice: Get a TBE then get tuned.

 

CT, you shouldn't be messing with crap like this without a tune. Don't install the fuel pump until you get tuned.

Yes, hitting fuel cut multiple times will throw an overboost CEL.

 

I ran mine with fuel pump, mbc, cams, etc... for about a month before the tune. You'll run rich, but I doubt it'll hurt anything.