GVR-4 GVR4 - Weird O2 Sensor Problem Need Help

[Dark_Horse]

This is on my GVR4. Mods are E16G. 2G exhaust manifold, 2G O2 housing, 3 inch downpipe/exhaust & DSMlink V3.

I have a brand new Bosch O2 sensor that I installed a couple weeks ago. I finally got the car up and running yesterday and initially the O2 sensor was cycling properly.

I idled the car in the driveway for maybe 20-30 minutes and the O2 sensor was working (cycling) perfectly. After about 20-30 minutes, the O2 sensor quit cycling and dropped to 0.02 volts. No matter what I did in DSMlink, the O2 sensor remained on 0.02 volts.

I turned the car off and started it back up and the O2 sensor started working correctly again. Then 15-20 minutes later, it did the same exact thing...Dropped to 0.02 volts and stayed there.

Any ideas? Anyone ever have a similar thing happen to them?

 

[Dark_Horse]

So in my quest to eliminate the problem with the O2 sensor volts, I did a few things. I replaced the O2 housing inlet gasket and I also swapped out the ECU for a known good one. Neither of those helped and the O2 volts would still drop to 0.02 volts after 10 - 20 minutes at idle.

I also did a sea-foam treatment - moreso to verify that I didn't have a MASSIVE exhaust leak...Nope. No exhaust leaks except for a very, very minor 1 from O2 housing/downpipe (after the O2 sensor).

As a last resort, I decided to replace the brand new Bosch O2 sensor with a Denso O2 sensor. What do you know...That fixed the problem. The only explanation anyone could give is that the heating element in the Bosch was bad.

Thanks for all the help BTW.