How can u tell if your stock 1-wire O2 is about to die?

[Blazer406]

Stock ECM.....TT wideband 6.0 chip...

The BLM's were running fine at idle when I drove the car last week...... now today..... I noticed the idle BLM's at 145....??? WTF?

The narrow band 02 is hovering around 450mV at idle with the cross counts doing as they should.....but the wideband is showing 11.5:1 AFR at hot idle. Doesn't add up......

Why would the actual AFR (shown on my wideband gauge) be in the 11's at idle and the ECM is pouring the fuel to it.....and it thinks the AFR is fine at 450 mV???

Just thinking I might be having an 02 issue instead of a vacuum leak.....which is the usual cause of BLM's climbing......

 

[bison]

The o2 sensor is likely shot. Tmk the tt chip idles in open loop so it isn't using the o2 data then. The light throttle cruise at running temp is a better test.

 

[jasjamz]

Have you been running leaded fuel? Is the engine vacuum right where it always is? If so, I would replace it.

 

[Blazer406]

The o2 sensor is likely shot. Tmk the tt chip idles in open loop so it isn't using the o2 data then. The light throttle cruise at running temp is a better test.

I had forgot about the OL idle..... makes me feel better......cause I was seeing it fall out of closed loop at idle today. I am still getting used to the PL.....first time I have actually run one was today......

Probably pick up an 02 tomorrow..... as I can't remember how old this one is.....

 

[Blazer406]

Have you been running leaded fuel? Is the engine vacuum right where it always is? If so, I would replace it.

No leaded fuel has ever been in my car..... just premium unleaded and alky.....

Don't know where the vacuum is...... never checked it......

 

[TurboBob]

the TT chips are closed loop idle for the first drive, then switch to open loop idle. So its learning the high blm then locking in.

You could probably reset the ecm and make the first drive a warm start and see if the idle will lock to a reasonable BLM.

If that chip has the right patch level, you could use the PL and change the BLM number yourself as well...

Bob

 

[Blazer406]

the TT chips are closed loop idle for the first drive, then switch to open loop idle. So its learning the high blm then locking in.

You could probably reset the ecm and make the first drive a warm start and see if the idle will lock to a reasonable BLM.

If that chip has the right patch level, you could use the PL and change the BLM number yourself as well...

Bob

That's probably what it was.......as I unhooked the ECU to install the PL......since I had not driven the car at all...... it probably "learned" the high BLM sitting in the garage....

About to install the 80's and another chip......might fix itself then.......