P0430 DTC?

Sorry that this is not a specific Explorer issue, but I bet the trouble code and possible solution would apply. I didn't find a Crown Vic newsgroup in this area.

I have a 1999 Crown Victoria with a 4.6L showing DTC P0430, which is "Catalyst System Efficiency Below Threshold (Bank 2)".

When this appeared, the car started having difficulty running at idle when the car was cool (would die and need restarting repeatedly). Once it warmed to normal operating temperature, the idling problem went away.

Someone suggested that code indicated DPFE may need replacing, but it's not cheap. Any other suggestions? I'm not a mechanic, but I'll try to do whatever I can to avoid the high costs at the dealership.

Well, throwing an EGR part at a catalytic convertor code sounds pretty odd. Part of the high cost of the dealership (the decent ones, anyway) is in accurately diagnosing the concern....

P0430 is usually generated when the PCM sees too much activity from the downstream O2 sensor - this usually doesn't accompany a running problem leaving me to think that the code is a symptomatic code and not a causal code.... My best recommendation is to address the basics... be sure that the car is in a good state of tune.... plugs, wires, filters.... compression is decent and you don't have the usual IAC or MAF problems. Once you are sure of the basics, clear the keep alive memory and recheck....

Remember that misfires and/or high oil consumption can recreate these types of problems (knowing the miles might help, too). Since your running problem occurs only with a cold motor and there are no other DTCs , I would consider that something else is giving the problem.... another thought - be sure you are running the correct oil... 5W20 is recommended. I haven't yet seen a 4.6 pump up the lifters, but it remains a possibility.

There is a very basic need to have some sort of understanding of the systems we are dealing with.

-- Jim Warman snipped-for-privacy@telusplanet.net