My car is ford contour SE, 2000, with 90k miles.

On last Sunday, when I drove on highway, suddenly I felt my car choked, and the speed went down immediately, I pushed with more gas, but the speed still couldn't go up, it kept choking. I had to stop at the curb and after a while slowly drove off the highway and back home. After a while, the check engine light on, I went to autozone, two codes, P0420 and P0430.

One year ago, the check engine light on, the code is P0430, then after several weeks, it went off automatically. And there was no problem when I was driving.

Now it is keeping on.

What maybe the problem? What should I check and where? Thanks.

This gets posted about once every week in the troubleshooting on CEG (Contour Enthusiasts Group) at www.contour.org since this is a common problem.

This one is a good read.
http://contour.org/ceg-vb/showthread.php?t=19346&highlight=p0420+p0430

The P0420 codes sounds like a clogged catalytic converter or an O2 sensor that is not functioning properly. The P0430 is the O2 sensor downstream of the cat on bank 2 is no functioning correctly. Could be a faulty cat, a faulty O2, or an exhaust leak.

The P0420 codes sounds like a clogged catalytic converter or an O2 sensor that is not functioning properly. The P0430 is the O2 sensor downstream of the cat on bank 2 is no functioning correctly. Could be a faulty cat, a faulty O2, or an exhaust leak.

Just so there is no confusion, the main cat is not monitored. There is no O2 sensor downstream of the main cat, only the precats. Consequently, only the precats are monitored.

The cats do have an 8 yr/80K mile warranty. You can try and see if the dealership can replace them even though your 10K mile over.

I would disconnect the battery and clear the codes and see the idle gets better and if the codes come back. Sometimes they the P0420 and P0430 are 'false' codes.

Thanks for all your reply.
What I'm mostly worried is choked driving, when I'm driving I always afraid it will break down.

Is it possible ford dealer to change my converter in warranty? since it is 8 years, but 90k miles already.

Is it possible ford dealer to change my converter in warranty? since it is 8 years, but 90k miles already.

Possible, yes. Likely, no. Its a huge job and about $1800 in parts for just the precats. Doesn't hurt to ask though.

Hi,

Thanks for your reply. I'll try two ford dealer close to my location.

Hi,

Thanks for your reply. I'll try two ford dealer close to my location.

If you decide to call them, don't disconnect the battery and clear the codes, just in case they make you come in. I would tell them the codes you are throwing though.

I asked help from dealer, but after check my vin number, my service date also expired, so I'm not in any warranty, :(

So I went to a garage store, after checked again, the technician said there's nothing wrong with the analyst converter and O2 sensors, but the software in the car need to be updated, and will cost 160$. So I didn't do that because he said that won't affect any driving.

Techician also got another two new codes which related to the car choking. he said because the transimission range sensor went bad, so I need to install a new one. He installed a new one to my car, and charged 300$. I'm still wonder if this is a reasonable price, because I have no idea of car.

I haven't tried my car on highway yet, and I'm not sure if the problem is solved, check engine light is off.

Acturally, transimission range sensor is around 90$, and labor fee is around 185$, so after tax around 295$.

My car is contour, 2000, V6.