Hello,
I'm clueless about understanding the freeze frame data for this PO 153 code I got today on my 2002 Blazer. Can someone please help me with what the freeze frame data means and what to do to fix it. Thanks!

 

You have a fuel control problem in closed loop. None of those freeze frame values are wildly out of bounds. Things to start with:

1) Can you graph the O2 sensors at idle?

2) Lets see those values in live data, cold engine, key on engine off

3) Any other codes stored or pending?

4) How does it run?


George

 

Thanks for the reply, I don't have a scanner capable of reading live data and the PO 153 code is the only one showing up. It also seems to be running no different than before.

 

I did have a pending PO 153 code about a week ago but it cleared by itself the next day.

 

I also just got through looking at the wiring and sensor and noticed that whoever had it before me had put some sparkplug foulers on the sensor! I had a new catalytic converter put on around 2 years ago so I'm wondering if those foulers could have something to do with the PO 153 code.

 

Those foulers are usually used to rig a faulty cat or sensor control and get the MIL off and/or pass inspection. Its not a proper fix. Which sensors have these foulers?


George

 

It's the sensor on the passenger side between the manifold and catalytic converter.

 

I have no experience with those devices but I think they are usually used on the downstream sensor. Was there damage to the pipe female threads that required a fix of some sort? Does this move the sensor out of the exhaust stream?

If any other member has knowledge of how or why these are used in this way, please chime in.

George

 

There's no damage that I'm aware of. I believe it would move the sensor away from the oxygen stream though. I'm wondering if I removed the fouler would it fix the PO 153 code.

 

If the threads are OK then I would remove the fouler and see what we get. Can you graph the O2 sensors after the fix? Also lets see fuel trims at idle after it warms up.

George