Mike6.0

I just picked up a 2000 ex coupe SOHC. When I got car I notice a different computer in the trunk. With current setup the car has a check engine light. Code reader will not connect to obd port to link up. The car has a lower than average idle at around 750rpm. I hooked up computer that was in trunk to connectors. Now the check engine light is off. When I started car it idles at 2000 for about two minutes than settled to 900ish and idles fine now. This computer does not fit back up In to kick plate of passenger side floor board. I have not driven the car yet. Wondering if anyone would know what is on this computer and if it may be safe to drive on. Only work that I know of done to car, engine wise, is full header back exhaust (skunk2) and aem cai. FYI I have already cleaned IACV

ezone

Post the engine ID number and the part numbers from both ECMs please.

Mike6.0

Hopefully I have right numbers for you I'm new to honda. The ECM that was in it first with a check engine light was 37820-p2p-a12
1213-226686

The ECM that's of larger size and got rid of code and changed idle a bit is 37820-p06-a52
741-342438 this ECM also says off road use only on tag

Engine ID If I found correct label is s40-2138972 or k4f-p48. Thanks for feedback looking forward to your input

ezone

99-00 EX MT, probably original.
Fits 94-95 DX/LX/DelSol S. OBD1.


It's probably been chipped or modified to work with engine mods or a non-stock engine.

Now let's see the engine code.

Not that number..... The engine code is stamped on the squarish pad like this





^In that pic the code is D16A6

Mike6.0

It's really greased up, but I believe it says D16YS. Even though I don't think the last number/letter is right. Could be a 5 I will have to take steel brush and clean it up when I get home to know for sure

ezone

Yeah do this.
That can't be an S...... so unless you find otherwise, it should be a 5.

It's got an HX engine?



Wiki:
D16Y5

• VTEC-E
• Found in :
  • 1996–2000 Honda Civic HX
  • 1996 Honda Civic EX (sedan Peruvian version)
    • Bore and Stroke: see D16 Series Engines
    • Displacement: see D16 Series Engines
    • Rod Length: 137 mm
    • Rod/Stroke: 1.52
    • Compression: 9.4:1
    • Power: 115 hp (86 kW, 117 PS) at 5,600 rpm
    • Torque: 104 lb·ft (14.4 kg/m, 141 Nm) at 4,500 rpm
    • Valvetrain: SOHC VTEC-E (4 valves per cylinder)
    • Fuel Control: OBD-2 MPFI
    • Head Code: P2J
  • 1996–2000 Honda Civic VTI
    • Bore and Stroke: see D16 Series Engines
    • Displacement: see D16 Series Engines
    • Compression: ?:?
    • Power: 127 hp (94.7 kW, 129 ps) at 5,800 rpm
    • Torque: 111 lb·ft (? kg/m, ? Nm) at ??? rpm
    • Valvetrain: SOHC VTEC-E (4 valves per cylinder)
    • Fuel Control: OBD-2 MPFI
    • Head Code: P2J
    • ECU Code: P2N
    • Piston Code : P2MY

Mike6.0

The body is an EX body. Has badges and everything. 2 door coupe 5 speed. For 14 years old the motor itself is pretty clean. Odometer has 125k

ezone

Is it a D16Y5?

What's the VIN of the car?

Do you have to pass an emissions test?

Mike6.0

Yes im almost positive is D16Y5 now. I live in Maryland so I will have to do emissions every two years until the vehicle is 20+ years old

ezone

You said it has a full header back exhaust, so I'm thinking it has no catalytic converter..... That might be a reason someone went with an OBD1 computer since it does not check for a cat. Just a guess though.

I'm not familiar with your particular emissions testing methods so I can't give much advice there.



Did you check out what codes it has when using the 37820-p2p-a12 control unit?

Mike6.0

I hooked up code reader but it wouldn't link up. I went to autozone and used theirs. Wouldn't pull anything

Stock 99

More likely a y8 check your stamp again

D16Y8

1.6 litre 16-Valve, SOHC VTEC Also available in New Zealand under the code D16Y6

Found in:
1996–1997 Honda Del Sol Si (US)
1996–2000 Honda Civic EX (US, UK)
1996–2000 Honda Civic Si (Canada)
1997-2000 Acura 1.6 EL (Canada)
Bore and Stroke: see D16 Series Engines
Displacement: see D16 Series Engines
Redline: 6,800 rpm
Rev Limit: 7,200 rpm
ECU Code: P2P
Piston Code: P2P
Fuel Control: OBD2-b
VTEC switchover: 5,600 rpm
Power: 127 hp (95 kW) at 6,600 rpm
Torque: 107 lb·ft (145 N·m) at 5,500 rpm
Compression: 9.6:1
Deck Height: 8.347 inches
Rod Length: 5.394 inches
Curb weights:
96-98 coupé (MT/AT): 1,116 or 1,132 kg (2,460 or 2,496 lb)
99-00 coupé (MT/AT): 1,140 or 1,161 kg (2,513 or 2,560 lb)
96-98 sedan (MT/AT): 1,142 or 1,165 kg (2,518 or 2,568 lb)
99-00 sedan (MT/AT): 1,140 or 1,162 kg (2,513 or 2,562 lb)

ezone

Any idea what the emissions test consists of?

If they have to hook up to the OBD2 port you may be screwed.
If they hook a sniffer to the tailpipe and you have no cat, you may be screwed.


Might need to trace out the communication lines between the computer and the OBD port.

Mike6.0

Just double checked. It is a D16Y8. But obviously I'm worried about the computer and emissions. I bought the car as a commuter. I could care less about having exhaust and all that stuff. But I also don't wanna pay an arm and a leg to have stock exhaust put back on and have computer diagnosed and all that other jazz. So hopefully we can figure this out

Stock 99

Just a couple of point here. The idle you described is normal for this engine and it does in fact idle at 750rpm and idle high at cold start. I'm not sure why a standard OBD II reader wouldn't read codes... it should. The original cat on this car was part of the header and very expensive to replace. You might be able to use a cat back with O2 sensor before and after. Is that how it is now? or are there 1 or no O2 sensors...that would explain the CEL.

Mike6.0

The headers have a spot for the o2 sensor I believe. It's a bolt that is plugged up. Trying to figure out how to attach images lol

Mike6.0

ezone

The connectors for the 2 original oxygen sensors should have been right below the upper radiator hose...and I can't see them in the pic.


Are there any o2 sensors on that exhaust anywhere? Under the car?

Mike6.0

There is connectors with nothing plugged into them right behind grille in engine bay. I'm not sure if there is a second o2 sensor. Car is lowered so I will have to figure out a way to get under there to see. But now that you mention the plugs and me seeing there is nothing in them then I doubt there is

Mike6.0

ezone

^That kinda looks like it would have been for the AC and condenser and fan parts that got removed -- because race car!

Mike6.0

Lol yea. An 18 year old def owned this car. Anyway I figured out where wire for sensor is supposed to be but I don't even see the wire not the connector that it's supposed to plug in to. So I'm confused. Looked under distributer by upper radiator hose and it's not there. If it's missing completely, any suggestions on what to do or buy? I plan on putting the other ECM back in

Stock 99

http://mattgadient.com/2013/03/13/re...-and-pictures/

Your connector should be the yellow circle in the pic.

Like Ezone said maybe you should figure out what the emissions test involves before you get too carried away. Most likely the CEL is being set off because your O2 sensors are missing which will effect your gas mileage but overall that's about it. The ECU that's in the car now sounds like the original (proper) unit. A pic of how it's not fitting in behide the kick panel might be helpful. The OBD II protocol is ISO 9141 so if your reader doesn't support that then it won't read.

If you just bought it then it might be worth contacting the seller and getting some more information/answers as to what's going on with the ECU/O2 sensors. I don't know if there's any protection laws regarding this where you live.

ezone

Figure this out first.
They could have been tucked out of sight.
They could have been moved to the rear of the engine harness, especially if someone moved the sensor locations.



Might need a pic of an original installed harness to see where the two sensor branches "break out" from the main loom so you know where to look on yours.
(Stock 99, do you have an identical car?)

Stock 99

Mine's a y7 but pretty much the same...no vtech.

The pics trace back from the O2 sensors back into the main harness before it enters the firewall. Those connectors by the drivers side headlight are for your missing AC.

Mike6.0

Update. I plugged stock ECU back in. I found a connector behind cup holders in carpet barely sticking out. Pulled carpet up and saw it was Unplugged. Restarted car, and now cel has gone out. So that's good news there in which o2 sensors are out of the equation. Only thing now is that I need to figure out how to get the communication from obd port to reader. Which is now my sole problem but if emissions can't read the ecu then they will fail and make you come back until it's fixed, this suspend registration. Still baffels me why it wouldn't communicate. It's a d16y8, weren't these motors only in 96 and below? Or am I mistaken cause mine is a 2000. Wondering if wiring is jacked somewhere and I don't know how to trace it and I don't wanna rip my entire dash out of car

Mike6.0

Also I don't see upstream o2 on headers nor the cable it plugs into on the mounting bracket as show in pictures.

ezone

Previous post:
D16Y8

1.6 litre 16-Valve, SOHC VTEC Also available in New Zealand under the code D16Y6

Found in:
1996–1997 Honda Del Sol Si (US)
1996–2000 Honda Civic EX (US, UK)
1996–2000 Honda Civic Si (Canada)
1997-2000 Acura 1.6 EL (Canada)

Does a scanner communicate now?
The O2s aren't out of the equation yet.


Look at your engine harness where the wiring was supposed to branch out, see if yours has been pulled a different direction, over the top of trans toward the back of the engine compartment.


Get under the car and look for relocated O2 sensors.

Mike6.0

No after that, still no communication from OBD port. I'll have to look at wiring harness to see direction of travel. If any pictures are available of what it SHOULD look like I would more than greatly appreciate that. So far we have already figured out half my problems. You all are awesome. I'm very grateful

ezone

Looking at the plug face (not the wire side)



#16 should be battery power,
#4 and 5 should be grounds


Stock ECM K-line (communication) should use ECM terminal A21 blu/yel wire to terminal (7) of the data link connector.
(continuity test)

#14 is SRS and ABS diagnostic line

(Honda does not use the same numbering scheme at the OBD plug as everyone else, but I did use commonly known terminals here)



SCS connector uses one wire (black) as ground, the other wire (brown) goes to ECM terminal A10.
SCS pic: