I have a 2000 F-150 4.6 4x4 and the check engine light has come on. I had it checked at a local parts store and the code they gave me is P0430. They thought it was the O2 sensor or a wiring issue. If anyone can give me a better idea on this I would really appreciate it. I would like to fix the problem the first time around. If it is the O2 sensor can anyone tell me which one it is or do I just have to go by trial and error? Thanks for the help.

 

A P0430 means that Bank 2 (driver's side) catalyst system efficiency is below the acceptable threshold.
Possible causes are Use of leaded fuel
Damaged HO2S (the one behind the catalytic convertor)
Malfunctioning ECT
High fuel pressure
Damaged exhaust manifold
Damaged catalytic converter
Oil contamination
Cylinder misfiring
Downstream HO2S wires improperly connected
Damaged exhaust system pipe
Damaged muffler/tailpipe assembly
Retarded spark timing

 

Thanks for the information. I have a new O2 sensor so I will try that first. Are the ones that are in the cat the same as the one before the cat? Hope that isn't confusing. I looked at this yesterday and saw that there was one in the top of the cat and it threw me off. Thanks for the help. This is a great site. It has alot of great information.

 

by "in the top" the cat do you mean that it is mounted to the cat or on the pipe above the cat?

It should be between the cats and the exhaust manifold.

 

There is one before the cat, but I also see one in the top of the cat. I will replace the one before the cat first. Hope to get it soon. Thanks for the help.

 

The code you're getting is for the furthest back sensor on the driver's side.

 

Thanks for the info. I hope to have this replaced by tomorrow. Time to get a tag and I have to face the sniffer.

 

Replacing that sensor was a pain in the A_ _!! I finally got it out though. So far the check engine light has not come back on. I'll give it a few days to see how it goes. Thanks for the help on this.

 

I have the same problem and am having the rearmost O2 sensor replaced today. If it fixes the problem should I expect the Check Engine light to go out on its own, or do I have to reset it?

My usual technique for reset is removing the battery terminal but I understand that will lose the settings in the management system which then could cause other running problems. Is there a better way to reset the check engine light manually, i.e. removing a certain set of fuses?

Thanks all.

 

Folks, Racerguy tried to explain the meaning of this code, but I think you all missed his point.

This code does NOT indicate a bad O2 sensor. The system monitors the inlet and outlet temperature of the catalytic converter via the O2 sensors. If the difference in these two temperatures is not great enough, that means that the cat is not doing its job. Replacing either one of these sensors is simply shooting the messenger.

What the code IS indicating is a bad catalytic converter. Of all the possible causes that Racerguy gave you, the common denominator is that for some reason the engine was probably running rich. It doesn't have to run rich for very long to cause this.

Good luck,
Doc
ASE Master

 

You of course might be right, but perhaps you should read his post again.

Here you go:

A P0430 means that Bank 2 (driver's side) catalyst system efficiency is below the acceptable threshold.
Possible causes are Use of leaded fuel
Damaged HO2S (the one behind the catalytic convertor)
..
..
..

I'm going to try this before forking out thousands on a new Cat or Exhaust system.

 

Yes, the sensor is certainly on the list of possibilities, however, if it were the sensor itself or the associated circuit, you would get a P015X code. The diagnostics in the system aren't dumb, they know the difference.

Good luck,
Doc
ASE Master