Else, you didn't ask me about this (your idea to gut your pre-cats) but we've come this far, so please allow me to throw my 2 cents in: I don't think it's a good idea..here's why...your Contour uses a Differential Pressure Feedback (DPF) EGR. Ford tests to see if the EGR is stuck open by checking the DPFE sensor at idle. The DPFE sensor tests for a differential in pressure (exhaust backpressure) across a restriction. As flow increases, DPFE voltage rises. Having exhaust backpressure is critical to the operation of this sensor. (Backpressure can be understood by using a funnel to pour oil into your engine. If you pour slowly enough, there is no backpressure.. the oil moves through the bottom of the funnel without backing up. However, if you pour faster, oil still flows, but also backs up, and rises in the funnel. Now you have "backpressure" at the bottom of the funnel because of the added weight of the volume of oil above the flow (at the bottom part). If you had a pressure sensor at the bottom, you would have a higher reading as oil is added). At idle, there is little or no backpressure in the exhaust. As RPM increases, backpressure begins to form (especially when accelerating and at cruise). On your Ford. this typically is 3 psi. (with an unaltered exhaust). If you alter the exhaust (the way you described), this would lower backpressure. The result: The DPFE sensor would send a false signal to the PCM (engine control computer), and fuel trim settings would not be accurate. After a short time of this, "rationality" kicks in. Rationality is the ability of the PCM to ignore a signal from a sensor if it is completely out of range in comparison with other input sensors. In other words, if the throttle position sensor reports throttle is partly engaged, and the MAP sensor says that manifold vacuum is low (a sure indicator of load) yet there is no backpressure, the computer will substitute a known good value. The problem is that this value will not vary, and the correct fuel trim cannot be maintained. In time, the long term fuel trim capability of the compute may max out. This may cause driveability and fuel consumption problems, which you may not have counted on. ................. Mike
techton
JoinedPosts by techton
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Oh catalytic converter, where art thou?
by Elsewhere inthe p0420 code is showing up again on my car... everyone i talk to agrees that the problem is with the catalytic converter(s).
the problem i am having is that no one (including the dealer) can tell me how many or where my catalytic converter(s) are.
i have heard people say that there is 1, 2 and even 3 catalytic converters.. so far the most plausable (and financially disturbing) thing i have heard is that there is one "catalytic converter" just before the muffler and two "pre-catalytic converters" attached to the exauhst manafolds on each side of the v6 engine.
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Oh catalytic converter, where art thou?
by Elsewhere inthe p0420 code is showing up again on my car... everyone i talk to agrees that the problem is with the catalytic converter(s).
the problem i am having is that no one (including the dealer) can tell me how many or where my catalytic converter(s) are.
i have heard people say that there is 1, 2 and even 3 catalytic converters.. so far the most plausable (and financially disturbing) thing i have heard is that there is one "catalytic converter" just before the muffler and two "pre-catalytic converters" attached to the exauhst manafolds on each side of the v6 engine.
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techton
Bad news, else....no warranty for you....it's either time or mileage, whichever is first.......btw, who says you have to fix this? It is true that it will put out a bit more emissions (possibly, or maybe not..you may have a "false" code)(one that indicates a problem that really isn't there). The only time you have to fix a check engine light is when your state requires a biennial (or change-of-ownership) smog check, and the presence of a check engine light being on fails you on the visual test. If you must take and pass the smog check (I don't know that you do), here is how you can do it.......Use a scanner to clear the codes....this will shut off the light (and you will also lose all freeze frames (stored failure information, but you don't need this). Then drive the car on the freeway between 40 and 60 mphfor at least 5 miles (you can drive out 2 or 3 miles, and then double back). This will run and set the monitors. Go back to the smog station, and without shutting off the engine (very important!) have him test the vehicle. No light, monitors set , pass. Even if you set a "pending code" during your drive on the freeway, it will not set the light until your "second trip". By not cycling the key (shutting off the engine), you are on your "first trip" still (get it?). Later, after the smog test, you will be on your "second trip" then, and the light may come on, but you will have passed by then. If you don't need the light off for the smog test, then you may consider letting this one go, for now, due to the expense involved. Even if you have that defective convertor (as your P0420 indicates, it will not affect gas mileage or driveability, or damage the engine. Hope this helps...Techton
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Oh catalytic converter, where art thou?
by Elsewhere inthe p0420 code is showing up again on my car... everyone i talk to agrees that the problem is with the catalytic converter(s).
the problem i am having is that no one (including the dealer) can tell me how many or where my catalytic converter(s) are.
i have heard people say that there is 1, 2 and even 3 catalytic converters.. so far the most plausable (and financially disturbing) thing i have heard is that there is one "catalytic converter" just before the muffler and two "pre-catalytic converters" attached to the exauhst manafolds on each side of the v6 engine.
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techton
Elso: forgot to add: On 99 Contour models with single exhaust, 3 HO2S are used.. on models with dual exhaust, 4 are used. You probably have dual exhaust. That means you have a pre-cat and a cat on bank 1, and a pre-cat and cat on bank 2. A PO420 and PO421 code means problems on bank 1.. A PO430 and PO431 are bank 2 problems, so you can isolate your problems to bank 1 (A little wordy, but, hey, you said you wanted help) Mike
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Oh catalytic converter, where art thou?
by Elsewhere inthe p0420 code is showing up again on my car... everyone i talk to agrees that the problem is with the catalytic converter(s).
the problem i am having is that no one (including the dealer) can tell me how many or where my catalytic converter(s) are.
i have heard people say that there is 1, 2 and even 3 catalytic converters.. so far the most plausable (and financially disturbing) thing i have heard is that there is one "catalytic converter" just before the muffler and two "pre-catalytic converters" attached to the exauhst manafolds on each side of the v6 engine.
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techton
Else...I gave you good advice, but allow me to add some more...your P0420 can be set for a number of reasons, including a bad cat..
1. Air leaks at the exhaust manifold or in the exhaust pipes
2. Catalytic convertor is damaged, contaminated, or has failed.
3. Engine cylinders misfiring, or the ignition timing is retarded.
4. Engine oil may be contaminated
5. Front HO2S (heated O2 sensor(the type you have) or rear HO2S contaminated with fuel or moisture
6. Front HO2S and/or rear HO2S loose in mounting hole (a possibility, seeing that you had the sensors changed...did the light come on shortly after?)
7. Front HO2S older (in age) than the rear
8. Fuel system pressure too high (check the pressure regulator)
9. HO2S wires improperly connected (a possibility, again, due to your recent repair)
Whatever the case, if you attempt repairs, you can verify the fix. You need to clear the codes (sounds like you have access to a scanner). Start the engine and drive the vehicle for 25 minutes - 20 minutes in stop and go traffic including 6 different steady speeds between 25 and 40 mph. Then drive on the highway for 5 minutes at a steady cruise speed. You've just run a catalyst monitor. If the cat failed, it will set a "pending code" (your scanner will tell you if you have a pending code. This means you haven't fixed the problem. A P0420 is a 2-trip code, which means that you have to cycle the key (shut off ignition), and run the "drive cycle" again, let the convertor fail again, and then the light will come on, if it still is defective, or you haven't found the real problem, besides the cat.. I hope this helps. Contact me if you need further info. Big Mike (techton).
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Oh catalytic converter, where art thou?
by Elsewhere inthe p0420 code is showing up again on my car... everyone i talk to agrees that the problem is with the catalytic converter(s).
the problem i am having is that no one (including the dealer) can tell me how many or where my catalytic converter(s) are.
i have heard people say that there is 1, 2 and even 3 catalytic converters.. so far the most plausable (and financially disturbing) thing i have heard is that there is one "catalytic converter" just before the muffler and two "pre-catalytic converters" attached to the exauhst manafolds on each side of the v6 engine.
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techton
Elsewhere...I am a licensed smog techian (Calif.) and also a licensed certified instructor (also Calif..) so allow me to set a few things straight......your car, being a 99, is OBD-II compliant, which means that the computer monitors all the emissions systems (on Fords, this is called "Diagnostic Manager") This diagnostic manager, when "code enable criteria" (the riight set of circumstances) is met, checks the operation of major emission systems (including the catalytic convertor(s). This is done while you are driving, and is not detectable. When this check is done, it looks for at least a 70% difference in oxygen levels from the pre-cat oxy sensor and the post- cat oxy sensor. The computer assumes that any less than a 70% reduction means that the cat is not storing/using the O2 (a bad thing).. The good news may be that your cat may be under warranty..if your vehicle is 49 state (Federal emissions), a likely thing if you are in Texas, then the 8 year, 80,000 emission warranty applies..this is a warranty on any emission part that costs more than 300 dollars (parts, labor, and diagnostic)(that cat definitely applies)...Your code is almost always cat related...Your Ford dealer should warranty...Also your O2 sensor problem seems misdiagnosed..all 4 do not go bad at once, and may have been warranty...any automotive questions, ask [email protected] (I don't mind, anything for a brother/sister ...Mike
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Chevy's for lunch in So. Cal anyone?
by ApagaLaLuz inalright, why should we let the northerners have all the fun.
why dont we meet up next week for lunch somewhere?
i was think making the chevy's in ontario, since it was mentioned before.
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techton
Chevy and/or Sally...e-mail me and we'll set it [email protected]
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Chevy's for lunch in So. Cal anyone?
by ApagaLaLuz inalright, why should we let the northerners have all the fun.
why dont we meet up next week for lunch somewhere?
i was think making the chevy's in ontario, since it was mentioned before.
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techton
I would be happy to meet for lunch...I'll even buy....Meetup in Riverside canceled for May, and I would like to meet new friends and swap stories.....Mike .
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Nice encounter with a JDub
by BoozeRunner inhey folks, i havent posted in a while, but this experience was worth telling.
last wednesday while at work (a family retail shoe store),.
an older sister from my last congregation came in to make a purchase.
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techton
My daughter was df'd in 95... at the time, the CO and I were selling cars together on the side... he told me I could still talk to her, that not all circumstances are the same, exceptions could be made.....some of the cong. complained then, but there was nothing they could do
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techton
min...why do we park on a driveway but drive on a parkway?
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I guess it's my turn to sit on the sidelines and watch in frustration.
by TheSilence init has happened... my sister is pregnant... and i have very mixed emotions about it.. i am so happy for her, i know they've been trying for a while and it's what she really wants.
it will make her happy.
and i love my nieces and nephews, i know i will love her child just as much.
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techton
I've taken matters in my own hands...my granson is 8, and I talk to him all the time about thinking for himself...my daughter and I discuss how these 2 kids (baby granddaughter 15 mons. old) can best be shielded from the hatred