2015 3.5 eb, I have 69,000 miles, recently I did a full amsoil swap, msd coils, denso TT plugs, jlt 3.0 catch can, banks ram air intake and ams turbo inlet tubes. Since then my mileage went from 19c and 24h to 12c and 18h. My truck is almost sluggish sometimes and I keep getting the dreaded p04db code. I’ve even tried the afe magic insert tube and replaced the crank case sensor. Each company blames it on the other. I’m to the point of either throwing it all in a corner of a garage or trying to tune it. Any and all advice would be helpful

 

Start removing the easy stuff first and check any change in mileage to find the culprit.

 

For years it has been a general consensus that Ford OE coils are superior to any of the aftermarket brands. I would start by swapping them back in unless there was a real problem with them before their removal.

 

I'd do exactly that.

Put a tune on it and grin from ear to ear. All of those items together don't come close to producing the gains a tune will/does.

Then, if you want to slowly add an item here and there it should make it easy to figure out what's causing the problem.

Either way I'd start with the plugs and coils. Use OEM as mentioned by 52merc

 

Tough love incoming:

So... you've added magic mystery oil that you didn't need, coils that aren't recommended and almost certainly not needed unless one failed early, plugs that aren't recommended, a catch can that you don't need, a "ram air" intake that isn't really ram air and doesn't do much, and turbo tubes that don't do a ton unless tuned.

No offense, but this is definitely not the greatest list of mods you could have done. Some new Motorcraft or NGK Ruthenium plugs and a quality tune would have netted you far more power than all this.

All that said, P04DB is a crankcase vent fault. I'd pull the catch can and see if that code goes away.

 

I didn’t wanna start from the beginning but I will lol
I bought this truck used from a ford dealer with 64,000 miles. After the throttle body went out in 4 lanes of traffic with my mom and 3 year old in there I thought maybe I should see what has actually been completed on it. The only maintenance that had actually been completed on this truck was oil changes 😂 so I went crazy with the ams oil cause “I’m a believer”. I also received another code because one of the fittings on the inlet tube was broken and glued,( so instead of 346 for a new stock tube) I “upgraded” to the ams ones. Also found that the front driveshaft was slinging grease all over the torque converter changed it. The plugs were rusted in there so I thought why not “upgrade” after reading forums those are the plugs I thought would be best. That was apparently a bad idea lol I believe the tubes and intake combo are what’s throwing the code, and the tubes are the main culprit of my mpg loss. But they will not return them. My question is get a tuner to trick the computer or just take the hit and go back with stock tubes? The ram air is a joke lol but I got a deal on it and the coils. But those coils and plugs will be coming out this week and I’ll probably throw that ram air in the corner with em. 😂

 

While the coils and plugs may be suboptimal, you, at this point, aren't getting misfire codes. You are getting a CCV code - and that points straight at the catch can, which could actually be harmful. I'd start my unbolting mission there - and a tuner isn't going to make that code go away. The tubes likely won't net you much improvement, especially without tuning, but they aren't harmful either.

If you don't know the history of the truck, I'd consider doing a complete fluids swap as well. Quality Motorcraft fluids will do you just fine, or you can spend 4X and run Amsoil for no real benefit if you believe!

 

10-4 man I’ll give that a try first. Thank ya