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Discussion Starter #1
My car's "Check Engine" light has been on for a few months and I decided to get it checked out. The codes it was giving were

P0442
P0401

Please help me out and let me know what these mean and what might have caused them. The light came on about 1 month after my intake was put on and the only other modification i have is a Flowmaster dual cat-back exhaust. So please let me know what to do. Thanks!
 

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MM's Resident Ricer
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your gas cap is loose
 

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Discussion Starter #4
Anyone have anymore ideas?
 

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P0401 - Insufficient EGR Flow.
P0442 - Leak in Evaporative System Detected.

Check for a possible vacuum leak, and check your EVAP system for possible leaks.
 

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MM's Resident Ricer
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442 is usually your gas cap being bad, it will throw an egr code, make sure the cap is good, and seals right, if thats not it, replace the EGR pressure sensor, if thats not it replace the EGR valve itself, if thats not it replace the EGR vacuum solenoid
 

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and if thats not it then you just wasted alot of money and you need to take it all back:D:D
 

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Discussion Starter #11
442 is usually your gas cap being bad, it will throw an egr code, make sure the cap is good, and seals right, if thats not it, replace the EGR pressure sensor, if thats not it replace the EGR valve itself, if thats not it replace the EGR vacuum solenoid
How much will this cost? What about the other code?
 

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MM's Resident Ricer
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first off replace your gas cap, its 5 bucks and yours could leak,
reset the code by undoing the negative terminal of your battery for 15 mins,
drive if it comes back get the EGR pressure sensor its about 60 bucks and undo the battery again and drive if it still comes back (which I doubt since EGR code on a FORD is normally the pressure sensor) get a new EGR valve about 120 bucks and do the battery reset. If this still doesnt fix it get a new vacuum soleniod will run about 50 bucks. If this doesnt fix it you have a vacuum problem and need to go to a mechanic. Also when you get a new gas cap get a new PCV valve and replace that as well
 

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Discussion Starter #16
first off replace your gas cap, its 5 bucks and yours could leak,
reset the code by undoing the negative terminal of your battery for 15 mins,
drive if it comes back get the EGR pressure sensor its about 60 bucks and undo the battery again and drive if it still comes back (which I doubt since EGR code on a FORD is normally the pressure sensor) get a new EGR valve about 120 bucks and do the battery reset. If this still doesnt fix it get a new vacuum soleniod will run about 50 bucks. If this doesnt fix it you have a vacuum problem and need to go to a mechanic. Also when you get a new gas cap get a new PCV valve and replace that as well
There is a slight leak of gas, but only after i fill it up. That lasts for about an hour at a slow rate, possibly coming out of the tube connecting the gas cap and gas tank. Would this do it? What is the PCV valve and do i need a special one or universal?
 

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MM's Resident Ricer
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There is a slight leak of gas, but only after i fill it up. That lasts for about an hour at a slow rate, possibly coming out of the tube connecting the gas cap and gas tank. Would this do it? What is the PCV valve and do i need a special one or universal?

Uhh its the gas leak man, get that fixed thats your problem
 

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Discussion Starter #18
Uhh its the gas leak man, get that fixed thats your problem
So would i need to do any of the other stuff u recommended then? If not, how to fix the leak? Would this account for the other code as well or only the egr one?
 

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So would i need to do any of the other stuff u recommended then? If not, how to fix the leak? Would this account for the other code as well or only the egr one?
Nope all you need to do is fix the leak and it will fix both codes. What is happening is fuel vapors that should be in the EGR system are being let out through the leak so your getting insufficient flow and the leak code.

To fix it find the leak and replace whats leaking. If it is the filler hose they sale it at autozone and a shop will put it in for about 50-80 bucks depending on my hard of a swap it is
 
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