The heater portion of the o2 gets power from the fp relay and ground through the ecu. Make share you have the reference signal grounded.

Jordan wrote:The heater portion of the o2 gets power from the fp relay and ground through the ecu. Make share you have the reference signal grounded.

So, let's pretend I'm clueless here ( ), which wire is the reference ground? From memory I think the green wire, pin 23, was grounded but I could easily be wrong...

Without looking at the diagram again, 23 is the signal wire. 47 or 46 is a reference ground that goes into the sensor ground bundle.

Interesting, sounds like that could definitely be it!

I had been following a 9000 diagram for the O2 sensor and the 3 plug sensor I bought had nothing in pin 3, which wouldn't you know, goes right to pin 47 so I'll bet I omitted that from the ECU harness. I'll have to take a look tomorrow and confirm but I would be willing to bet that is the issue, thanks as always!

Well in my infinite wisdom I actually had put in the reference ground in pin 47, so no luck there... but disconnecting the ECU did clear the codes and the IAT has gone away which is nice, the O2 sensor CEL does pop up randomly which is annoying but the car runs well enough I can certainly live with it. I still have an annoying dead spot pulling out in 1st gear but if I really have to accelerate I can just slip the clutch a bit to get the revs up.

Anyway, the tailpipe situation is really annoying me as I had to use a mix of awful band aid solutions I'd be ashamed to share on this site, and seems to be leaking again. At this point I don't have enough time to take it to the local exhaust shop to have a more permanent solution welded on before I head out of town next week. Its a shame there just aren't many cat back options for c900s these days so I'll have to think about what direction I want to take with it.

Posting this just because this site is slow these days so I'm once again trying to shame others with my boring content

Hoping this motivates others and most certainly me to get a jump on some projects this summer! Heres my list so I can hopefully stay on task:

1) Redye the sun-bleached leather interior. Need to decide on a color, leaning towards slightly darker than stock but still tan

2) Modify the rear SPG panels to fit the vert, probably refinish those eventually as well

3) Get ABS light/sensor figured out and replaced

4) Theres a power steering leak, I should track it down and replace, hopefully by 2024

5) Shorten the tailpipe



You're absolutely right that things are a bit dusty around here..

Ugggh dont get me started

The Skandix exhaust sounds nice but looks awful, like a JDM car, as soon as I get a chance its off to the muffler shop to get a new tailpipe section welded on!

Shortening the pipe before the tailpipe by a couple of inches works just as good.

Yeah, for flat nose cars the long tail pipe looks fine, but slant nose cars it is like 3in too long.