Searched and read all the P0401 threads, been lot of help. Just a couple more more questions.

I got the P0401 code on the CEL. Figured it was dirty ports leading to the EGR valve after reading all the posts. Tried to get the EGR vavle off, but the backside bolt (the one the brake booster cable attaches too) got real tight after I got it about half way out. So tight I was afraid to keep torquing on it. Hopefully, some lube will take care of that tomorrow. Tried to get the the exhaust manifold tube nut off, No go. Don't have the right size wrench and the crescent didn't really look like a good idea. Will try all this again tomorrow at the shop where I have better tools. I went ahead and took the throttle plate off to see what the throttle elbow looked like. Sure enough, I could see two huge carbon nipples poking out into the throttle elbow. I scraped some of the crap out with my finger but then realized the chunks were falling down into my intake, thought better of it and quit. OK, here's my questions. Those two ports must run all the way back to the EGR valve, so will I need a wire of some kind to completely flush those of carbon?

Also, when I took the intake tube off the throttle plate, there was a factory sticker there saying NOT to clean the throttle body with TB cleaner because of some special coating. How important is this? I'd like to clean it up while I have it off but if the "special coating" is crucial, don't want to mess anything up.

Thanks.

 

in answer to your first question, the egr ports come out from the egr valve as a single hole about a 1/2 " in dia. this hole goes straight across the back of the elbow, and the the 2- 1/8 inch ports go staight into it, forming a 90 degree angle. which is why they get so blocked up (bad design). soak the elbow in deepcreek and clean it with anything that works, thats not to abrasive.

the throttle body is coated with teflon, to help prevent build up. so just clean it with a good cleaner that states coating safe on the lable and a soft rag. after your done i would recomend doing a seafoam treatment to clean the rest of the system. the TB and Elbow is only the carbon you can see.

 

Unless you have extremely high mileage, the ports are probably not plugged. Do an EGR valve test by pulling vacuum on it while idling, and if that tests good by causing the engine to stumble, the valve is working and the passages are clear enough. The metal cased DPFE sensor is a notorious break-a-matic part. They corrode and hang up, telling lies to the PCM which prevents proper EGR flow. Ford redesigned the part and the new ones are plastic. I bought the Wells SU282 sensor at Autozone and it's a metal cased POS just like the original Ford part. Put on a new plastic Ford DPFE sensor before going to all the trouble to clean ports if the EGR valve test comes up good. I'm going to change out the Wells DPFE sensor on my truck by 30K miles, if it makes it that far. Taking off the DPFE sensor is a 10 minute job, and if the two ports are corroded, then you've probably found your problem.

 

Here is how to remove the throttle body/intake plenum from a 4.6L engine. The 5.4L engine is not too much different.

http://www.fordf150.net/howto/throttlebodyclean.php