do i need a new ecu??

[shepworldwide]

sup guys n gals

i have a 99 civc hx and i'm going to drop in a b16 "b16a2 i belive from a 99 si" anyways do i need a new ecu??


also how can i tell if the ecu is made for an auto instead of a stick?

thanks
j

[civickiller]

whether your stock hx ecu will work or not, i suggest getting a ecu that was made for the b16 because if you use the hx ecu, the b16 will have the same vtec cross over and rev limiter as the hx, i highly doubt that the hx can rev up to 8500, and if you dont rev up to 8000 then your not even hitting peak hp

as far as i know, you cant tell by the numbers on the ecu, but this is just a guess. but you can test it out in your car because an auto ecu will have lower vtec engagement and a lower rev limiter.

[kaytec4door]

well yes you do need a new ecu because of vtec and the fuel and a bunch of other stuff but if you go with the b16a2 motor that is the si ecu and they all are five speed. but if u get a pr3 ecu it may be auto. it may not the only way to tell if it is a pr3 is to open it up and it will have at or mt stamped on the inside
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[civickiller]

well first of all, the pr3 ecu is a obd0 ecu, and it wont work on the b16a2, it might work but youd get thrown a code that would always stay up so i stay away form that. as far as i know the civic si b16a2's are obd2, which means you either gotta get a b16a2 obd2 ecu, or get that ecu conversion obd2 - obd1, then get a p30 ecu. it would be cheaper just to get the obd2 ecu, i think idk research it

[Fishcat37]

Originally posted by civickiller
whether your stock hx ecu will work or not, i suggest getting a ecu that was made for the b16 because if you use the hx ecu, the b16 will have the same vtec cross over and rev limiter as the hx, i highly doubt that the hx can rev up to 8500, and if you dont rev up to 8000 then your not even hitting peak hp

as far as i know, you cant tell by the numbers on the ecu, but this is just a guess. but you can test it out in your car because an auto ecu will have lower vtec engagement and a lower rev limiter.

The Hx is NON-VTEC. The only 6G civic models that were VTEC (SOHC or DOHC) were the VX,EX, and the Si. So, if you used the HX ECU, VTEC wouldn't engage...and the car wouldn't run right due to the smaller engine (greater fuel requirements, spark/ignition requirements, etc...). You are right about the PR3 ECU, it is NON-OBD/OBD0 so it wont work on an OBDII motor. Just get the 6G Si ECU.

[civickiller]

fishcat you need to do alittle research.

5thgen
nonvtec
dx, lx, cx

vtec
ex,vx, si
------------------------
6thgen
nonvtec
dx,lx, cx

vtec
hx,ex,si

[shepworldwide]

thanx killa

[Fishcat37]

civickiller- I stand corrected the HX is VTEC....forgot about the economy VTEC...or VTEC-E. it's kind of like the 5G VX then i guess...as far as economy vtec. On the PR3 ecu, you can unscrew the metal covers...and on the upper level circuit board will be a white stamp : MT for manual trans...and AT for automatic trans.....not sure if the OBDII ecus are like that tho