[Help] CEL code keeps coming back even after repairs
Hi everyone,
My '00 Cougar keeps having this check engine light coming back on, with the trouble code of P0401. I've looked this up and it's mentioning it has to do with the EGR... Well, problem is so far that I have literally replaced every component that this has had to do with and it still keeps coming back. I've so far... •Replaced the Solenoid •replaced the valve pressure sensor •replaced the EGR valve itself •Replaced the vacuum elbow that connects to said EGR valve
I've tried resetting the system and doing a proper drive cycle, but the CEL still keeps coming on. And problem is I need to make it go away so I can go in for emissions, since this state requires it. Needless, the amount of effort, time, and money I've had to spend trying to make this go away is driving me batty, especially when there should be no reason for it to return.
So far my attempts at Google-fu aren't coming up with anything else that could help me make this problem go away... at the least, long enough for me to go do the emissions thing and get that all squared away. -- Because, f*ck Sony
If everything is working properly, then it sounds like the ports in the intake are clogged with carbon build up crap. Depending on vehicle you have to pull the intake to clean the crap out. Might be able to do it on car but I'm not familiar with the cougars. -- You don't quit playing 'cause you're OLD. You're old BECAUSE you quit playing!!
santy likely nailed it. Too bad you didn't try some diagnostic work before you threw all those parts at it.
To be fair, a lot of those looked like they were on the car since it was new.
Well, after seeing that video, today I was motivated enough to head over to the shop to borrow some necessary tools, and since I couldn't find someone with the time to give it a try, did it myself.
The intake there on that video looked clean compared to what I first saw... it was solid black lining those grooves, up and into the intake manifold! Which is quite the shock considering that even the EGR valve itself that I'd replaced was clean before I moved to this state.
In any case, spent 30+ minutes (likely about an hour) picking away at it with a flat-head screwdriver until I could see the grooves again on the intake and then cleaning as much of it off of the throttle body.
This was *after* picking the crud out with the screwdriver
That doesn't look so bad, but...
euuugh!
Then after that, went in and bought a big ol' can of carb cleaner,and doused both ends of it. It indeed is a far cry in difference compared to what I started at. I wonder if this is what it is like to give someone a nose job? I just know that at least for a while there, she has accelerated quite a bit more quickly since doing it.
Needless, the amount of effort, time, and money I've had to spend trying to make this go away is driving me batty, especially when there should be no reason for it to return. 
