I bought a 98 hatch as of late. I haven't been in the Honda game since 2002, I had a 94 coupe with a B16a2. Anyhow....Drove the car everything seemed to be in order, no CEL, a little slow but then again these days Im used to driving a ram V8. So I shrugged it off because I was looking for a gas saver/and a future moderate N/A Daily Driver performance machine...I was informed by the owner that a D16y8 had been swapped in which had less miles than car previously had on the CX motor which I assume was the D16y7(155k). Ok so far so good. Well I bought the car and a day later CEL pops on. I ask owner and he says its a o2 Sensor. Hmm...ok.. So FIRST indication something was wrong was I took it to AutoZone, Oreilly's, and Advanced auto parts and no one could get the Code reader to connect to my Diagnostics port... Huh? Yeah exactly what I said wtf smh... So I use the old Jumper trick to see the CEL flashes and get the codes. At first I had an IACV and Secondary o2 sensor code.. I bought the down stream o2, installed, disconnected the battery to reset ECU, and voila CEL was gone. 10 Miles later CEL is back on. Read codes again and now its just the Secondary o2. So I do some digging...D16y8 I found was the EX version which of course should be VTEC but I never spotted the Vtec solenoid so I knew something was up... So I found out that what they swapped in was a d16A. It has a p2a-10 Head and looks like a p2E-L32 ECU.
I thought hmm maybe they were supposed to put on the more expensive downstream o2 for the y8. So I took the y7 o2 ($60) back to the store in exchange for the more expensive y8 version ($120). Install the new o2, clear the CEL and 12 miles later its back..... Another kicker...The primary o2 is at the top of the exhaust manifold where it should be. Now the secondary is in the front of the car at the bottom of the exhaust manifold. I don't know if that's how the CX is supposed to be but I know the y8 Secondary should be underneath the center console? Correct me if Im wrong. HELP

The car runs fines when I clear the code, maybe a little bit of a lack of power but then again I really cant tell. Its smooth, quiet, and SAVES gas. Secondary o2 comes on and it still runs fine, but for some reason eventually the IACV code hits and the car starts to bog and jerk a little at low rpms.

I need to identify what do I have here.. in order to move forward and I'm hoping that the D Series specialists here will be able to guide me forward.

I took some pictures to try to help provide a visual of the parts. Any help is greatly appreciated.




HEAD




D16A Block ID




ECU

 

Primary and Secondary o2 Sensors

 

Based on the information you provided, here's what I think you have:

The stock 98 Civic hatch comes with a D16Y7 engine, just as you thought.

The current engine has a D16a block from a Honda Domani and a p2A-10 head probably from the original stock D16Y7 engine. The P2E ECU is also probably the original one for the car, which should be fine for the current set up. My guess is that if this presumed head swap was done correctly, the whole set up should work as well as the original stock D16Y7 engine.





Therefore, what's needed is to figure out why a code reader doesn't communicate with the ECU and why the codes are popping up.

With proper attention on your part, and our help, you should be able solve what are likely minor issues.

 

ECU



I appreciate that. I think you're right has to be something minor because if I disconnect the battery to reset the ecu, CEL goes away and car runs great. Then eventually code 63 pops up again and later causes the IACV code to pop up (14 if Im not mistaken). I just bought this car 3 days ago, and wasn't sure if all the components were compatible mainly the ECU. Im trying to understand what the previous owner did or didn't do correctly.


On the ECU I noticed a butt connector on the bottom not sure what for but I understand some wiring may have had to been done for the o2's (Im assuming because I have no idea.)

 

Code 63 may be related to the wire modification I see for the lower, secondary O2 sensor. It looks to me like the previous owner found out that the catalytic converter was bad and, rather than replace it, he chose the less expensive option of inactivating the secondary sensor to hide the CEL code from the bad cat. The wiring modification you see is probably a resistor meant to cause the ECU to think the secondary O2 sensor is fine. Apparently, the wire alteration job was botched. In summary, I predict that if you fix the secondary O2 sensor and bring it back to stock that you will see a cat CEL code pop up.

Determine what ECU pin is also modified:

http://www.phearable.net/images/tech...schematics.gif

Pin numbers are viewed from the wire side of the connectors.



Regarding the failure of the code reader to communicate with the ECU, start by checking whether hood fuse 43 is blown:



Do you have a multimeter?

 

I do have a meter. the pin with the connector is the only out of place thing I see so far.

 

And Yes SIR! The 43 fuse was blown. I'll be sure to replace it today.

 

As for the pin, looks to be on the c connector pin 4 for the CYP Sensor? I'll double check to make sure I don't see anything else out of the ordinary.

 

Is the yellow wire alone wrapped with red insulation or are other wires also bundled with it?

The Yel wire at pin 4 is one of the two CYP sensor wires. The CYP sensor is inside the distributor. You haven't posted any CYP sensor CEL code, so the wiring there may be fine.

 

That should allow the code reader to communicate with the ECU, and also restore function to your dome light. One possibility is that the fuse blew due to a short in the dome light part of the circuit, so report back if the fuse blows again after installing a new one.

 

Just took a closer look...No CYP codes... but pin 1 and 4 are jumped together and then looked like 11 and 14 were jumped together...smh

 

Hmmm...maybe the D16a block lacks the CKF sensor required for the D16Y7. The wire mod may have been done to bypass the need for a CKF sensor. Without a CKF sensor, the ECU won't be able to see engine misfires and report those specific trouble codes. Other than that, the mod should not have any other effect.

You can Google search "CKF trick" to see if you find a match with what you see.

Edit: Yep, the CKF bypass trick:

http://technet.ff-squad.com/ckftrick.htm

 

Sounds about right considering both the M and P side for the CYP and CKF are jumped

 

I'll get that fuse tonight and hook up a reader in the morning to see what I get. I'll keep you posted. Thanks for your help

 

ok, so I replaced the #43 fuse under the hood and it allowed me to use the OBD2 reader.
Four Codes popped up
#1
P0158 (ENG)
Oygen Sensor Circuit High Voltage Bank 2 Sensor 2
(CURRENT)


#2
P0136 (ENG)
Oxygen Sensor Circuit Bank 1 Sensor 2
(CURRENT)


#3
P0138
Oxygen Sensor High Voltage Bank 1 Sensor 2
(CONFIRMED)


#4
P0136
Oxygen Sensor Circuit Bank 1 Sensor 2
(See P2270, P2271) (O2 Stuck Lean, and O2 Stuck Rich)

 

The scanner I'm using has a built in o2 tester in the programming so I gave it a shot and it said Max voltage for the o2 sensor1 is 2.0v.
Sensor 1 measures .08volts
Max voltage for o2 sensor 2 is 1.275v
Sensor 2 measures 1.275v

What am I missing? There's an overvoltage problem on sensor 2?

 

Well I swapped the primary and secondary o2 sensors to see what happens. Went for a drive and no CEL as of yet. I always fiddled around with theharnes area undernearth the Intake manifold, so If I drive around some more with no issues Im going to suspect a damaged wire somewhere that perhaps I moved around off of a shorted position and will inspect closer back there tomorrow.

 

Sounds like you're good to go.

 

**Crossing fingers** Thanks for the help everyone its greatly appreciated. I'll be sure to keep posted

 

No cigar....even though I swapped the primary and secondary o2 still got the same codes for secondary o2.
How can I verify it's not a damaged or shorted wire?

 

This is a shielded wire with the White/Red inside I believe that's the signal for the Secondary o2





The white/red Shielded wire was spliced to this Brown/Black wire.





White/Red wire at the D Connector or the ECU





Brwn/Blk is spliced to the white/Red? so why would the White/red be cut to begin with?

I think we almost have this figured out. Anymore advice is GREATLY appreciated. I don't want to splice the white/red back together in fear that I'll do some kind of damage. HELP
What do I do?

 

Im beginning to suspect the same at this point. Question I have is whats the brown/black wire for and can I just resplice the white o2 signal wire. I think that's exactly what this guy did...if the brown wire is factory spliced like that to the White/red, then all he did was cut the White/red from the o2 so he didn't get that cat code. I think I'm about to splice it back and see what I get.

 

Yeah, that extra component is not stock. Make it gone one way or another.

 

So after splicing back in the secondary o2 and driving 30 miles I have yet to see any CEL! Thanks guys for the help couldn't have done it without yall. Long live Honda-Tech Nation

 

Wiring is the one thing that gives me the heebie jeebies. You and RonJ smacked that out in record time!