obd-II to obd-I
03-14-2007, 06:02 PM
#1
Registered member
Thread Starter
Join Date: Dec 2004
Location: RAF Lakenheath, UK
Posts: 1,727
Likes: 0
Received 0 Likes
on
0 Posts
obd-II to obd-I
How hard is the conversion......is there any kits for it? What all would i need. Anyone willing to help out?
its for a 99 honda civic ex
its for a 99 honda civic ex
03-14-2007, 06:29 PM
#2
AKA: SHY_GUY
Join Date: Dec 2004
Posts: 4,175
Likes: 0
Received 0 Likes
on
0 Posts
03-14-2007, 06:31 PM
#3
I Love to Hate
Join Date: Mar 2006
Location: Va Beach
Posts: 6,777
Likes: 0
Received 0 Likes
on
0 Posts
Re: obd-II to obd-I
conversion isnt too tuff, 5 easy steps.
First, Reuse your existing OBD2 engine harness and add the respective VTEC wiring and Knock sensor if you own a non-vtec 96-00 civic OR find a 96-98 EX engine harness which already has the vtec wiring & knock sensor embedded into it.
Second, Find a set of B-series OBD2 injectors OR cut & splice the OBD1 injector plugs and adapt them to your OBD2 engine harness.
Third, Find a 96-00/OBD2 B-series alternator OR sell/trade the OBD1 B-series alternator for a 96-00/OBD2 B-series alternator. The plug is a square type on the 96-00 alternators and has 1-2 more wires leading to it, whereas the OBD1 alternator plug is a bigger round plug and has less wiring going to it. So there might be an issue if you try to rewire it...your best off fnding an OBD2 B-series alternator though.
Fourth, Find a 96-98/OBD2 B-series distributor which will plug n' play w/your DX engine harness OR they say you can convert your OBD2 distributor plug to OBD1 spec by repin it to a dual OBD1 plugs and will accept & utilize an OBD1 distributor. I've never done this myself and I find a big pain in the ass (I personally hate rewiring stuff)....I suggest you find a 96-98 B-series distributor to make life easy on yourself.
And finally the ECU.
If youd like to go OBD1 ecu, purchase a 99-00/OBD2>OBD1 ecu jumper and simply use an OBD1 ecu. JDM OBD2 ecu's programming is similiar to OBD1 programming as far as looking at sensors. It looks at the same exact sensors an OBD1 ecu does.......but for the US version of OBD2 ecu's programming, they look for a few more sensors which makes OBD2 a hassle.
US OBD2 ecu's look for these additional sensors:
- CKP (an integrated crank sensor thats found & embedded on the oil pump)
- 2nd 02 sensor
The CKP sensor is the big downer, since OBD1 and JDM OBD2 engines do not have this sensor. If you want to add this sensor, you need to change your oil pump to a US spec 96+ B-series oil pump. Again, you can easily avoid all this frustration & wasted $$$ if you go with a JDM 96-98 ecu or the OBD1 route.
First, Reuse your existing OBD2 engine harness and add the respective VTEC wiring and Knock sensor if you own a non-vtec 96-00 civic OR find a 96-98 EX engine harness which already has the vtec wiring & knock sensor embedded into it.
Second, Find a set of B-series OBD2 injectors OR cut & splice the OBD1 injector plugs and adapt them to your OBD2 engine harness.
Third, Find a 96-00/OBD2 B-series alternator OR sell/trade the OBD1 B-series alternator for a 96-00/OBD2 B-series alternator. The plug is a square type on the 96-00 alternators and has 1-2 more wires leading to it, whereas the OBD1 alternator plug is a bigger round plug and has less wiring going to it. So there might be an issue if you try to rewire it...your best off fnding an OBD2 B-series alternator though.
Fourth, Find a 96-98/OBD2 B-series distributor which will plug n' play w/your DX engine harness OR they say you can convert your OBD2 distributor plug to OBD1 spec by repin it to a dual OBD1 plugs and will accept & utilize an OBD1 distributor. I've never done this myself and I find a big pain in the ass (I personally hate rewiring stuff)....I suggest you find a 96-98 B-series distributor to make life easy on yourself.
And finally the ECU.
If youd like to go OBD1 ecu, purchase a 99-00/OBD2>OBD1 ecu jumper and simply use an OBD1 ecu. JDM OBD2 ecu's programming is similiar to OBD1 programming as far as looking at sensors. It looks at the same exact sensors an OBD1 ecu does.......but for the US version of OBD2 ecu's programming, they look for a few more sensors which makes OBD2 a hassle.
US OBD2 ecu's look for these additional sensors:
- CKP (an integrated crank sensor thats found & embedded on the oil pump)
- 2nd 02 sensor
The CKP sensor is the big downer, since OBD1 and JDM OBD2 engines do not have this sensor. If you want to add this sensor, you need to change your oil pump to a US spec 96+ B-series oil pump. Again, you can easily avoid all this frustration & wasted $$$ if you go with a JDM 96-98 ecu or the OBD1 route.
03-14-2007, 07:00 PM
#4
TurboPipingSystems
Join Date: Jul 2003
Location: USDM Land, Va Bch
Posts: 1,483
Likes: 0
Received 0 Likes
on
0 Posts
Re: obd-II to obd-I
For a 99 ex, all you need is an OBD2b to OBD1 conversion harness and an OBD1 P28 ECU. Simple plug and play dude. Requires no assistance....
03-14-2007, 08:48 PM
#5
Registered member
Thread Starter
Join Date: Dec 2004
Location: RAF Lakenheath, UK
Posts: 1,727
Likes: 0
Received 0 Likes
on
0 Posts
03-14-2007, 09:20 PM
#6
braap braap
Join Date: Jul 2003
Location: Portsmouth
Posts: 14,535
Likes: 0
Received 0 Likes
on
0 Posts
Re: obd-II to obd-I
And good thing your runnig the obd-1 ecu. From what i hear, the motors run different timing maps.
Someone else will chime in and break it down for me.
03-14-2007, 10:37 PM
#7
Registered member
Thread Starter
Join Date: Dec 2004
Location: RAF Lakenheath, UK
Posts: 1,727
Likes: 0
Received 0 Likes
on
0 Posts
Re: obd-II to obd-I
03-15-2007, 02:29 AM
#9
TurboPipingSystems
Join Date: Jul 2003
Location: USDM Land, Va Bch
Posts: 1,483
Likes: 0
Received 0 Likes
on
0 Posts
Re: obd-II to obd-I
Yes, P28 OBD1. Remember that P28 comes in both OBD1 and OBD2 (from Delsol late models). In your case, you will also have to change the distributor.