Son's car needs ideas

Done, didn’t find any.

I believe this may be a large part of your problem. You are trying to use a OBD 1 ECM with an OBD 2 engine. Is this a JDM Engine? If it is you may need to get the P5P ECM. I’ve got the wiring schmatics for the P13 ECM. Let me see if I can find out the diffrence between the P13 and P5P ECM. I’ll need to try and find the P5P schematics first. I will try and post the diffrence later.

This is a info that I put together using my Haynes Service Manual, The Swap Guide, and info I got from http://www.autoserve.8m.com/OBD2ab1.html

OBD2a, OBD2b and OBD1 Conversion Table

OBD2a 1st Pin Callout
OBD2b 2nd Pin Callout

Pincallouts-------Function--------OBD1—Color
A01--------B05—Injector 4---------A02-----Yellow
A02--------B04—Injector 3---------A05—Light Blue
A03--------B03—Injector 2---------A03------Red
A04--------B11—Injector 1---------A01-----Brown
A05--------A08—SO2H-----------No connection on OBD1
A06--------C01—PO2H-------------A06—Orange/black
A08--------B12—VTS----------------A04—Orange/White ----------------------------------------------------------------or Green/Yellow OBD1
A09--------B20—LG1----------------A26-----Black/Red
A10--------B02—PG1----------------A23------Black
A11--------B01—IGP1---------------A25—Yellow/Black
A12--------B23—IACV---------------A09—Green/White-------------------------------------------------------------------Or EACV Black/Blue OBD1
A15--------A06—PCS----------------A20-----Red-----------------------------------------------------------------------------Or-PGS Red/Grn OBD1
A16 A16 FLR A07 Green/Yellow Or Orange/Black OBD1
A17 A17 ACC A15 Black/Red Or Red/Blue OBD1
A18 A18 MIL A13 Green/Orange Or Green/Red OBD1
A19 A02 ALTC A16 White/Yellow Or White/Green OBD1
A20 B13 ICM A21 Red/Green Or IGP1 Yel/Grn OBD1
A22 B22 LG2 B02 Brown Or Brown/Blk OBD1
A23 B10 PG2 A24 Black
A24 B09 ICP2 B01 Yellow Black
A27 A20 FANC A12 Yellow/Green Or Blue OBD1
C01 C31 CKFP No connection on OBD1
C02 C08 CKPP B15 Blue/Green
C03 C20 TDCP B13 Orange/Blue
C04 C29 CYPP B11 Orange
C05 A27 ACS B05 Blue/Red Or Blue/Black OBD1
C06 A24 STS B09 Blue/White Or Blk/ Green or Blu/Red OBD1
C07 A10 SCS D04 Brown Or Orange/Red OBD1
C10 B21 VBU D01 White/Blue Or White/Yellow OBD1
C11 C22 CKFM No connection on OBD1
C12 C09 CKPM B16 Blue/Yellow
C13 C21 TDCM B14 White/Blue
C14 C30 CYPM B12 White
C15 C10 VTM D06 Orange/Green Connected to VTS on OBD2a or Light Blue OBD1
C16 A26 PSW B08 Brown/Red Or Red OBD1
C17 C05 ALTF D09 Pink Or White/Red OBD1
C18 C23 VSS B10 Yellow/Blue Or Orange OBD1
D01 C27 TPS D11 Pink/Black Or Red/Black OBD 1
D02 C26 ECT D13 Red/White Or Yellow/Green OBD1
D03 C17 MAP D17 Pink/White Or White/Blue OBD1
D04 C19 VCC1 D19 Yellow/Green Or Red/White OBD1
D05 A32 BKSM D02 Greem/White
D06 C03 KS D03 Red/GreenOr Red/Blue OBD1
D07 C16 PO2S D14 White
D08 C25 IAT D15 Red /Yellow
D10 C28 VCC2 D20 Yellow/White
D11 C18 SG2 D22 Green/White
D12 C07 SG1 D21 Green/Blue Or Blue/White OBD1
D14 A23 SO2S No connection on OBD1
D16 A30 EL D10 Green/Red
IABS A17 Pink OBD1

Hit the post button before I had it finished! Download the file and it has everything I was trying to post but easier to understand.

I ran the ECU check engine light codes and it threw code 41. This code indicates “Primary Oxygen sensor - heater circuit malfunction” Besides replacing the primary oxygen sensor what else could this be?

“I ran the ECU check engine light codes and it threw code 41. This code indicates “Primary Oxygen sensor - heater circuit malfunction” Besides replacing the primary oxygen sensor what else could this be?”

Do you have some kind of repair manual? It should tell you how to test the O2 sensor while its in the car. I might have the test procedure for a 95 Prelude. Don’t know if it will help. Let me check and I will try to post the procedure

I guess the file That I’m trying to attach is to large for this posting, it’s 37.8 MB. I can send you this service repair manual in a PDF file that covers a 1993 Prelude. It tells how to check and test for not only the code 41, page 304, but also most other codes that might be set. If you want it let me know and I will send it to you. I will need to know your email address to send it to you. If someone on this forum know how to attach this file please let me know.

Did you check your ECM to see if it was wired correctly? Is it wired for OBD 1 Or OBD 2? Just wondering.

it looks like it’s wired for OBD2

reset the ecm and code 41 went away and now it is throwing no codes. Still running rich.