hey guys, I have a B20b swapped in and I’m using the stock B18a’s ECU. I would have figured that with the B18a’s inherent problems with running rich, that running a slightly larger motor on the same setup would remedy that. Yet I’m still runnung quite rich. Any non Hondata/S300 fixes for this? I have a short ram intake, headers and a custom 2.5 inch exhaust all the way back, with a magnaflow high flow cat. I’ve already reset the computer to let it relearn itself a few times, with no results. fairly new NGK’s and wires. Any suggestions? Thanks.
Nobody else has had this problem with their B20? Wow
running rich
dude u my just need to get a adjustable fpr that helped out when i had the same problem with mine 
I don’t think an adjustable FPR would help that problem. Lowering the fuel rail’s pressure wouldn’t change the injector’s duty cycle or their rate.
Oh well, I guess this is a good excuse for some engine management parts!
How do you know it’s running rich?
black sooty plugs even when you run it hard and hot and immediately check the plugs. Poor gas mileage, and black film around the exhaust outlet. funny enough, I passed the texas smog test.
Sounds pretty rich. Have you checked for any vacuum leaks? I know a bad o2 sensor will cause this too.
My B20Z ran like a complete POS before I had it tuned (wouldn’t even idle right). I’m pretty sure mine was running lean though. Check all sensors, vacuum lines, check for CEL codes, and get it tuned in some form or fashion. After having mine tuned with Crome Pro on a dyno, it still running great 3 years later.