Thread: Regrounding the O2 Sensor

Thats great to hear!

DC Scotty gave me his 1527 O2 sensor, since on a B13 the ECU can't really use the features of it.

So far it seems like it increased my gas mileage, not totally sure about performance though.

Great to hear your success Darrin! Yes, we now definitely know that a SSAC header does not ground the 3-wire O2 sensors well. Any now, we have another witness!!

Vadim & I swapped O2 sensors early last week. The one that Im testing got rid of my pig rich running but now its just the opposite, pig lean!! I think its just a bad O2 sensor. Purchasing a non-Ebay sensor is the way to go... #)@($&*!_)#$*@

BUT, Please check your readings on a test drive at operating temperature. Look at the A/F mixture and make sure that you are not running LEAN... And at idle, rev it to 2500k rpm, make sure the O2 reading bounces 5 times in 10 seconds... Just a precaution...

This thread is not dead... Its not finished.. :o hehe!!

BTW SkyShepherd, what year and model of SR do you own?

Actually, Vadim, I'm using it on my Calum-ized NX2000 M/T ECU (1991 Highport), and I have seen no issues so far.

I was watching it toggle rapidly between rich and lean during the mode II test using Conzult on the laptop, but I'll take her for a spin and verify on a road test. Thanks for the heads-up on that Scotty. I was happy when the new sensor arrived from Rockauto; nice new box with the Bosch number on the seal, full instructions plus hardware for the splice into the existing OEM plug.

FWIW, when I performed the mode II test on the old O2 sensor, the test indicated the sensor was stuck on perma-lean (not good with a high comp. engine!), so I'm feeling pretty lucky I caught it and installed the countermeasure. The very same sensor performed flawlessly on the old cast iron manifold (which is why it was transferred to the new engine). The potentially poor grounding on the stainless header is a real concern for long term engine health!

Thanks again guys! Any further testing you need from a fresh install, let me know, I'd be happy to help!

Darrin

Oh, almost forgot. Scotty, on the numbers stamped on mine, at the end of a series on the top line, it ended with the three-digit grouping 727 (possibly a coincidence, but pretty unlikely). So for mine (which, according to the box is USA made), the actual model was stamped right on it.

Darrin

Thanks for the update SkySHepherd!

Interesting another OBDI car haha . Now is that sensor the Plano type or thumble?

Plano:


Thimble:

Plano Jane-o! I was a little leery, to be honest, as it replaced a thimble style, but I can't argue with success (so far, anyway). I will try to get a run in tomorrow with the laptop running conzult, and watch the A/F, output voltages and temps to verify. Standby for further...

Darrin

Well several points to add:

An Electronics Guru who designs analogue integrated circuits took a soldered joint and some weight from it at room temperature, after about a month it pulled out. The guy was Bob Pease of National Semiconductor ( one of their chief designers)
A proper crimp will have the same voltage drop as a straight unjoined piece of wire of the same diameter.
The heater pulls about 2 amps or so when cool/cold, so a .4 volt drop that is causing lean at idle means about 0.2 ohms resistance through the stainless header.

The LC1 wideband needs to be on the horizontal portion of the downpipe, they are not as tolerant of the high temperatures in the std bung holes. quite close to the cat would be best for a long life.

The wires are teflon coated to cope with the downpipe temperatures inside the connector, but anymore than a few inches away from the header and any ordinary wire of the right gauge would be fine.

Some people try and crimp then solder, that stops the wire from being able to flex properly and it WILL break sooner than a plain crimp.

It may be why I had idle issues in my last car, currently its an eGT red top hatchback with the std header.

Mike

Amazing but great news! The plano works too.
Thanks for the input.. I will need to try the plano one..

Hey Vadium.. You're in DC today.. I want to try the plano one! Call me!

Awesome, yep pick me up and we'll be set