Contour Enthusiasts Group Archives Forums Branches California Facing the inevitable... ...pre-cat issues.

Ok, here is the situation. My SVT Contour is throwing the P0420 code, which is a bank 1 O2 sensor code.

From what I have been able to read up, its not the sensor itself that is typically at fault, but the pre-cat. There are a few remedies that will temporarily fix the code (involving B12, cooking the cat, etc) but the inevitable fact of the matter is that the cat is toast and will need to be replaced. My car is past the 70K mark (just turned 80K), hence past warranty replacement (CA car) and as you know they are quite costly.

What seems to be the preferred choice is two options:
1. Gut the pre-cats and run MIL eliminators
2. Replace pre-cats & manifolds with headers (MSDS) and use MIL eliminators.

Both 1 & 2 are now fully dependant on the main cat now, most likely a new Y-pipe/cat combo added at the same time as the headers if that option is taken.

I fully understand the concept of the MIL eliminators, they "fool" the ECU into thiking everyhing is ok with the O2 sensors even though the sensor signals are dynamic, transitioning between 0 & 1.0V depending on the mixture.

I also understand that the pre-cats are used primarily during startup and as long as the car has been warmed up, it should pass the sniffer part of the test. I'm hoping, with the engine bay being so packed, its will make it difficult to see if the pre-cats are there or not.

What I want to know, which is why I posted this in the CA part of the forum is... ...who has done this personally? I've read alot of, "yeah I've heard it works or so and so did it". No first hand accounts.

I don't want to drop a G only for things not to work out.

Any input is appreciared & TIA,

gut 'em.

im running a 3 liter /hybrid motor with a 11.25 compression...and when i gutted my pre-cats and smoged, it passed...cleaner than my stock 2.5 liter.


You should be fine gutting them, and using the mil eliminators. make sure you warm it up with a good half hour drive before your smog test.


Also, MSDS Headders are a better route as they give you more power, but i did not have the money at the time to get them. MIl eliminators do work!!!

the only probelm is if you go to a goody to shoes shop, they will not smog you if they see the headders. Go to a vietmanies shop, that barely speaks english...they won;t care if you have headders or not.

or if you know someone who knows someone, you can usualy get away with it.

But YES, gutting pre-cats i had no problems passing..and headders are not problem wither , besides mentioned above.

Lupe

does anyone here know the official reason why the headers are not carb approved?

i did it on mine, and i have passed smog 2 times, once with the 2.5 liter and once with the 3 liter. its way cheaper then buying the precats.

Thank you all for the advice.

I really need to spend some maintenance time on the car (remove/clean/reinstall) the TB & UIM. Need to see how hard it is to remove the exhaust/manifolds/y-pipe.

For now I am just going to run a can of B12 for a fill up or two and change the upper 02 sensors.

Hopefully that will buy me enough time to finish my 84 SVO Mustang (Fabulous Fords Show at Knotts) and then I can give the Contour some quality time.

Thanks again, the input is appreciated. For you local SD people that may read this, I hope to attend the meet in Feb. If I am in town I s/b able to.