WHY???

Hello
I have a 2014 V6 Sport.Ha 101k miles. Dis tune-up. cleaned MAF/TB, replaced PCV valeve, now it seems to be having a problem I cant figure out. from a stop, give it gas, feel slight hesitation, finally start going. floor it. works ok. but sometimes while on the fwy it will start stuttering, I slow down and it clears. Have switched gas, still no difference, no lights or codes come up. HELP!!!!!!!!!!!!!!!

 

Plugged cat? Faulty coolant temp sensor or CPS? Does yours have a replaceable fuel filter? If so, has it been replaced?

 

Did you disconnect your battery prior to cleaning your MAF?

 

Check all the vacuum lines, make sure one didnt slip off

 

I don’t think I have replaceable fuel filter. What’s CPS?

 

Yes sir I did. Done twice.

 

One of the coils may be about to go out. I have had those malfunction without throwing any codes on other trucks i have had. Same symptoms. Does it stutter on a hard stop? Like a misfire? How about when it is idling?

 

Sounds like a vacuum line is off.

 

No sir. It’s smooth when idling

 

Some of the other folks mentioned a vacuum line. Good advice. I'd look to that first if I were you then. Some mechanics have a smoke machine that they can plug up to your vacuum system, if there is a leak or a hose off they will find it pretty quick

 

Yup, I'd say the vacuum line at the back of the intake box is off.

 

Camshaft position sensor

 

Or that too is a possibility. Have you had cranking problems?

 

I choose not to answer this question. Haha (no)

 

What is "Dis tune up"?

 

How old is the battery & alt? Take a voltage reading, should see ~14 volts when charging. ~12 with truck off.

 

TB gasket in good shape?

 

Problems that occur after fixing something are usually due to something the mechanic did or didn't do and rarely because of a new problem. I would bet back-tracking will reveal the problem. What did you clean the MAF with? Make sure the vacuum line to the Fuel Pressure Regulator is attached and not cracked. Did your PCV valve rattle when you installed it? The rattle indicates the valve is working and isn't a defective new part.

 

I will tell you WHY???? I purchased OEM plugs from Amazon. Decided to replace with plugs purchased from dealer. problem fixed. turns out plugs from Amazon even though were OEM, the heads were small. contact with coils were not solid, replaced with Dealer plugs, I could feel the difference in how much better it seated, runs great again. Thanks for all the good advice.

 

Amazon has some platinum plug scams going on.

Friend had a set that were fake and engine ran rough.