Ive been working on a 97 base that I bought a couple weeks ago, and I have a wiring issue that I can't figure out. The car was throwing CEL for primary O2, so I jacked it up and found that the primary o2 isn't plugged up...I began looking on the harness and couldn't find the 4 pin connector (C118). I pulled the harness out of the car and took off all the tape and couldn't find any cut wires. Where the ecu harness comes out at the strut tower the wires for o2 are there, but not on the engine harness side. The harness has the plug for atts, and one other unused plug at the stut tower (atts??). My question is do all 5g preludes have the atts plug? The helms manual looks like the primary and secondary o2 go the ecu on the body side of the harness not the engine harness. Does the SH engine harness have an o2 sensor plug? If it does I guess Im going to buy a new harness.

 

Anyone ever seen an sh engine harness?

 

Yeah, they have a big plug for the ATTS sub-harness, but still have an HO2S connector. The ATTS sub-harness connector is pretty large, put up some pictures.

 

I've got my SH harness out of the car right now. Tell me exactly you want me to look at or take pics of and I can do that for you. Iirc from the last time I looked at the helms wiring diagrams, the O2 sensor wiring is not the same between Base and SH. Let me see if I can find it..

 

Look at page 11-15.

 

yeah Ive looked at that. It says that on the base c143 connects to c282 at the strut tower on Base. On SH it shows c293 going straight to ecu, or is it saying that it also connects at c282?

 

No you're right. It looks like it joins the 282 loom going to the ecu but before the shock tower plug, ie. on the chassis harness between the ecu and plug.