P0430 What to do?

[2000SVTC]

My 2000 SVT (~136k mi) threw a P0430 code/MIL last weekend on a longish trip.  Looking at the forums and Ford CD, that's a catalyst inefficiency alarm on the front bank.  Apparently this works by comparing the switching frequency of the O2 sensors before and after the front exhaust mainifold "precat".  If the after sensor switches too often compated to the before, the assumption is that the cat is nor up to par.

 

I just now connected my PC scantool to the car while idling in the driveway.  Both "after" sensors are acting about the same as one another, and are definitely switching slower than the "before" sensors.  So the cats are certainly not totally dead, otoh this was not under any real load.

 

 Reading the forums it sounds as if this failure can be random, a sign of a bad cat, maybe a bad sensor or connection, or maybe a function of a too-tight factory OBD threshold.   Apparently there is or at least was a factory reflash loosening the limits to eliminate false failures.  Alternatively an MIL eliminator can be installed, which if I understand correctly is a low pass filter circuit to damp the signal from the "after" sensor to always read "good" on the precat.

 

I've got no other codes and car runs reasonably well (good power and economy) so if there's a fault I guess it's either downstream sensor, wiring, or in fact a worn out cat.

 

If it comes back after clearing and I find nothing else wrong, and if I'm not willing to replace or gut the precat cat, I think I have two choices -

 

Install MILs

 

or

 

Get the reflash.  Does anyone know if this is still available and if the dealer service department can tell if it has already been done?

 

Or any other thoughts?

 

Al Seim

2000 SVTC

 

 

 

[Terry Haines]

At 136,000 I'm sure all 4 02 sensors are tired and slow. First I would change all 4. 02 sensors..the pre cat meltdown issues have long gone, I have seen this many times ..in most all cases new 02 sensors is the cure...