Well this has me baffled.

This is a fresh built LS/VTEC, Its the second time it was built...The first time there were mechanical issues which forced me to completely start over...Before those mechanical issues I took care of ALL error codes being thrown and there was no check engine light anymore.

Now onto this build, The only thing's that have changed is:

Last time I used a B18A and this time I used a B18B.
The B18B was bored over to 81.5mm,The B18A was Standard bore.
I took the knock sensor from the B18A and put it in the B18B.
I wired up a car stereo system while waiting for the block to get back from the machine shop,Which is obviously completely wired independent of the engine wiring harness...I didnt tap into anything under the hood except the battery.
I upgraded all my ground wires under the hood to 4 gauge,and the battery ground to 0 gauge.

I fired it up for the first time tonight and the check engine light came on quickly, I peeked over at Hondata and to my suprise their were no error codes being thrown.

What gives? Im pretty experienced with building these cars, and even more so on the electrical side of things and I have never seen this before.

1997 Honda Civic Hatchback
B16A2 Top
B18B1 Bottom
Hondata S300
P72 ECU
OBD2>OBD1 Harness

 

Does the engine run? Did you forget to remove a jumper wire from the service connector?

 

Yep Runs good besides the surging idle.....And yes I rewired the IACV already and its working fine and responding to changes in Hondata.

I got my first code today during 20 mile breakin..Knock Sensor!

 

Check for a vacuum/intake air leak, bleed the cooling system, and clean the FITV, if you have one.