Based on what someone else discovered here, I wanted to report on my FF44 situation.

I had the infamous Marelli meltdown a few years ago. It melted the insides of my secondary cat. It also pretty much fried the O2 sensor.

As I have not driven the car much since my date with a retaining wall, I wasnt worried about the FF44. But now that the car is driveable, I wanted to address it.

I replaced both sensors with Walker brand sensors. The FF44 still remained.

Today I installed Bosch sensors. Have driven about 10 miles so far.

The code is cleared!

This may well be to due with the 250ms response time of the sensors.

The car also runs smoother.

 

You might get more responses if you tell us what car you have???

There is a TSB (18-57) but it is a VIN specific (and maybe Country specific?) bulletin.

bob

 

Its in my profile, but I guess I need to put it in my sig.

1992 5.3L

I have the TSB, but it is no applicable to my MY. But Ive done the additional grounding none the less

 

Excellent. Glad it worked out. Seems genuine Bosch is the only way to go for O2 sensors.

 

Any ody want a next to new set of Walkers. 15 miles on them