My lil brother bought a used 2000 Civic Si with a rebuilt B20B with a B16 head with a Skunk2 Pro intake and 70mm throttle body, and a DC Sports 4-2-1 header and Greddy cat back exhaust. The car starts and runs ok when cold some times but when it warms up it leans out and stalls then will not restart. When you try to restart it it some times pops like a small back fire and gets hard to turn over for about a second or 2 then goes back to cranking and no starting for a day or 2. I have run my OTC I-Pro scanner on it and logged the data from the engine and only can find lack of fuel with the O2 sensors and I have a brand new AEM wide band O2 guage in the car to follow as well. The fuel pump turns on for prime and primes 45 psi for fuel, I checked the timing belt and distributor settings along with the Apexi VFAC settings plus plugs cap and rotor and they all look good. MAP and TPS look good along with the air temp sensor coolant temp is good too. If anyone has any ideas for me to look for I would greatly like the help.

Thank You

 

VAFC? Problem #1 right there. Take the car and get it professionally tuned. There is no stock ECU for a B20VTEC, because that is not a stock motor.

 

Problem is in MA where I live we need an inspection sticker and the factory ecu has to be in the car for the OBD2 scan so the registry sees the factory ecy with vin number in it up and running with no engine codes.

 

ecu

 

Then your little brother is fucked. He could try a GSR ECU, which would be closer, but there is no factory ECU that will run a 2 liter, B series, VTEC motor 100% correctly. It has to have the same VIN, too? That's...are you sure about that?

 

Massachusetts Vehicle Check

Going through that, nothing says that the VIN in the ECU has to match the VIN of the car. It only says that the VIN on the firewall/dash has to match the VIN on the registration. Give a GSR ECU a shot, see if that helps. You might have to do some creative wiring to bypass the butterflies, but I'm sure there's a way to do it if you put the time and effort into it.

 

Run usdm obd2a p72 ecu or find a usdm p73 obd2a ecu. Do not attempt to try an usdm obd2b gsr/type r ecu because they have the immobilizer chip. Hope to god the em1 still has all of the emissions stuff in there.