Hey all, I have searched the forum and haven't found much of anything about doing a B16B (99-00) swap into my 99 Em1. It's not a complete swap just the longblock and sensors/etc.
My understanding so far, it's a fairly simple swap but I am more concerned with the electronics part of it.
Would it be easiest to buy an EK9 ecu rather than use my b16a2 one? In the searches I have done I read conflicting information.
Basically I don't have to worry about emissions, but I also want the most functionality out of my car as well. Meaning I don't want certain things that are important to stop working. Any information is greatly appreciated!

 

From my understanding, the Type R ECU is mapped differently. Typically people buy it and plug it to their B16A(2). Flipped the other way around, I think you would be restricting the B16B with a B16A2 ECU.

 

Yeah if it's less problematic, I would rather get an ek9 ecu.

 

Am curious what is leading you to do this swap. I have an EM1 as well and am wondering if something went wrong and the a2 was trashed somehow.

 

I was dead set on just rebuilding it, I've kinda been a snob about keeping it strictly oem+.
Currently mine has a leaking valve/low compression on cylinder 3. I was about to buy the complete b16A2 swap HMO had and someone else bought it from under me.
The next day they posted 2 B16Bs with approx 78k so I decided to do something with a little more power.
It was a spontaneous decision but I'm not mad about it.
I will still keep my b16a2 motor and rebuild it eventually..keep it as backup but i have zero intentions on selling it.

 

Ah that makes sense. Yeah, I know all about the "eventually" thing.

I assume you got an obd2 b16b, which would probably prevent a check engine light for the cfk sensor, but would also agree that you're probably going to limit the performance of the b16b by running the a2 ecu.

 

It's a 99-00 b16b so my assumption is obd2..I was thinking best route would be just buying the ek9 ecu to minimize as many potential issues as I can..sounds like my stock harness should be okay though.

If anyone has different advice i would love to hear it

 

The JDM B16B "Facelift" ECU (from a JDM '99-00 CTR) will be the ONLY plug-n-play solution for your '99 Civic Si chassis. Your engine harness will plug into all of the common sensors and devices found on the B16B... the CKF will not be present and some of the emissions components may be different, but those items will not be recognized by the JDM ECU anyway. This will run the engine well, but it may not pass inspection/emissions testing in your area if required. If you try and run the B16A2 (P2T) ECU, you will have distinct problems. Your issues will manifest if you need to have the car inspected/emissions tested in your area. Assuming that you are: The oil pump and lower timing cover will have to be removed from the B16A2 and installed on the B16B so that the CKF sensor can be utilized. Your fuel rail, with the evap/purge solenoid, will have to be removed from the B16A2 and installed on the B16B intake manifold. You will need to source a vacuum port for the hose inlet. Finally, for the ECU, there is no direct plug-n-play solution in the USDM market... the ITR would be the closest version, however, since it is designed for the 1.8L displacement "R" engine, it will run richer than necessary... that is, if you can get it to even start. The trouble here is that in order to get a version of the ITR (P73) ECU that works in your chassis, you would have to find one from a '97-98 ITR. You would also have to use an OBD-2B -> OBD-2A ECU harness adapter in order to plug it into your current engine harness/ECU plugs. If you source a '00-01 P73 ITR ECU, it will plug directly into your engine harness/ECU plugs, but that ECU has an Immobilizer, and because your Si chassis lacks the matching immobilizer ring and specialized key, the engine will never start. I am unsure of a way to defeat this system and this is why I suggested the older style ECU in my explanation above. IF inspections/emissions testing is not required in your area, and you want the car to run perfectly, the BEST ECU for your B16B would be a TUNABLE one... and there will be many choices that can provide all that you need to do so. Each will require specific hardware and wiring changes and you will need to acquire all of the associated items needed to support the chosen system. A couple of solid examples would be Hondata S300 and a Link HC96X. Once installed, you get the car to a Tuner and have it Professionally Tuned.

Good Luck.

 

This is also my recommendation.

 

thank you! Exactly the type of write up I was seeking. Really appreciate it 🙏

 

You are most welcome.