DTC p1400

Good afternoon.

You have too much back pressure going to the sensor. That is a result of a catalytic converter being clogged and the exhaust cannot flow freely through the system. it is backing up into the sensor.

You will need to replace the catalytic converter. they come as an assembly with both together.

Roy

Replace the catalytic converter. Sounds right to me. Thank you so very much for your time and consideration of my problem. You are providing an invaluable service free of charge. That is impressive in today’s money driven economy. Thanks again for your knowledge and expertise. You are appreciated.

You are welcome.

We are here to help.

Roy

Hey is there two catalytic converters in this car? And if so, are both presumably bad? Or could it be just the one? And how difficult is it to change? Does it need welding to install, or does it bolt on? And I also assume it does need to be replaced with a new one? And not just break the insides out of this one and reinstall it? I’m sure that would interfere with sensor readings to the ECM as well as proper back pressure in the exhaust. Just curious.

They come as one unit. both together. you can buy separately but not recommended.

is this the U motor?? that would be the 8th digit in the VIN number

Roy

Yes it is a U motor.

Thanks. Attached is the converter assembly from rock auto. You should replace with this assembly. there are several available but walker is the best brand to buy.

Roy

https://www.rockauto.com/en/catalog/ford,2003,taurus,3.0l+v6+ohv,1415214,exhaust+&+emission,catalytic+converter,5808

Thank you. I will check into getting one and attempt to install. Do I need to replace 02 sensors as well?

No, just change them over to the new converter

Roy

Now I am confused. Trying to locate exact catalytic converter. They have front driver side converters, front passenger side converters, center converters, rear converters, and y pipe converters. It appears the y pipe converters are for DOHC engines. Which I believe mine is an OHV and not a DOHC. So eliminating the y pipe converters leaves me with a front driver side, front passenger side, center, and rear to choose from. And the prices for these converters seems outrageous to me. Some of them are priced more than the car is worth. $2200 at one place. Would I be better off to buy a universal fit and take the car to have I welded on? Wouldn’t I come out cheaper this way?

If you got the one from rock auto as I sent you and you took it to a shop and had them change it you would be looking at around 500

Roy

That link to Rock Auto directed me to a page starting with Ford asking me for the year of car. Then it proceedes to ask for model, sub model, engine type, then the category or parts. Where I have to direct it to the page with catalytic converters. There are probably 15 or more different converters on this page starting with a rear converter, then a front y type converter, then a right converter. These are followed with several other converters including rear main converters as well as center converters. Knowing the engine group being 3FMXV03.OVF4 it still isn’t clear to me which of these converters I need. I apologize for the confusion. I am fairly knowledgeable about most vehicle trouble shooting and repair. But this is an area I have never encountered and therefore am not very familiar with. I thank you for your patience I in dealing with my issues.

No worries. you said your 6 th digit was a U. This is the converter you need

https://www.rockauto.com/en/catalog/ford,2003,taurus,3.0l+v6+ohv,1415214,exhaust+&+emission,catalytic+converter,5808

So just to clarify,
this Davidco, part #59086, rear converter for $91 is the right one?

no, the 59071. the one you are looking at is a warm up converter. that is not the failure. it is the front 2 converters.

Roy

Well I have ordered the converter. Should be here on Tuesday. I’ll let you know the out come. Thanks again for all your help.

No problem, glad to help

The converter came in today. But nothing else was with it. It said it comes with all necessary hardware, bolts, flange gaskets, and heat shields. I do need new bolts and gaskets, don’t I? I can’t use the old ones, right?

yes, you can use the old ones.

Roy

Oh. Okay. Well let’s get it on the lift and see what I can do with it then.

sounds like a plan

Roy

Well I finally got the old converter off. But the new one doesn’t have threaded holes in the flange gasket on one end like the old one did. And the holes on the other end of the old flange gasket holes had grooves in it where the splined studs fit into. Where the new one is drilled smooth. Can I just use heat resistant bolts to replace the old studs? Or does it need to be threaded and splined like the old one was?

Can you post a picture of what you have

In this picture the old flange gasket bolt holes are threaded. Where the stud bolt passes through the other half of the flange and then threads into the converter side of the flange. Where the new one isn’t threaded and would need a nut on it to tighten down.

This picture shows the old flange stud holes with grooves in it that the splined head of the stud goes into to hold the stud from turning when you put the nit on the other side of the flange.

This picture shows the new flange bolt holes drilled smooth without grooves for the splined head stud to hammer into.

nuts and bolts are good to use.

Roy

I hate to bother you with all the little details. But I really hate to do a job incorrectly. And you definitely know your craft inside and out. Again, I appreciate all your help and direction.

you are not bothering me at all. I am here to help you.

only the factory OEM would have all the studs pressed in. thats why it would run around 1200 for the part.

Roy

Wonderful. I will proceed.

Okay. So after approximately 16 hours of labor, I did manage to successfully install the new converter. Started the car and drove it for about a minute and a half. It ran great. Better than it has since I’ve owned it. Then, it blew the passenger side hose off the DPFE sensor again. So no more good running. Very significant power loss. Irratic shifting of the transmission. I am completely baffled by this. Any ideas?

Oh yeah. And it is also throwing a DTC p1400-EGR valve position sensor.

ok did you look at the sensor itself?? from all the issue with the cat converters, the sensor may have been damaged.

Roy

So would that be the DPFE sensor? Or the EGR valve position sensor?

Dpfe or some call it delta p

Roy

Okay. Thanks. I’ll check that sensor.

Okay, so I hae been out of town for a couple of months and just now getting back to this 2003 Ford Taurus. I do not know if you will remember my case or situation or not? As it has been a while since my last post. But if you do recall? I did replaced the DPFE sensor once again, and upon trying to start the car, the brake pedal travels all the way to the floor. So no brakes now. The fluid level was low so I filled the reservoir and still no pedal. Could this be vacuum problem with the brake booster or a master cylinder failure problem? I also checked each wheel cylinder for leaks and there are no apparent leaks.

No, from the sounds of it, you either have a leak or the master cylinder itself may be the issue.

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

Okay, so this car has had some issues that you have helped me with over quite a long period of time. I apologize for taking so long to reply. Just to recap. I have replaced the PTFE sensor (original problem). Progressed to replacing the two front catalytic converters. Then had an issue with a bad master cylinder. Replaced the master cylinder this past weekend. Bench bled the master cylinder. Then bled all 4 wheels. Drove car around the block, and the PTFE sensor blows off at the hose connections again. Something is still not right with this PTFE sensor. Any ideas of where I should look to next? I am sick of throwing parts at this problem. Is there a way to determine exactly why the PTFE sensor is continually failing? Can vacuum pressure be a problem? I guess I need to get a better understanding of what the PTFE sensor does and what other systems are affecting it or are affected by it.

Did you replace the hoses on the DPFE as well before?

Roy