I have a f150 4.2 v6 2002, I started getting a stuttering (like a miss) when starting up from the cold and also when driving on the freeway at various speeds and sometimes when on side roads, I have also noticed a clunk every so often not all the time, I have changed the plugs, wires, coil pack I have sprayed the maf sensor, new air filter, new fuel filter, I did pop a couple of lean sensor codes (401 I think) but changing the previously said stuff turned that off, now I suppose I could change all that stuff again as it did work for a little while but its going to be expensive doing this every few weeks, its becoming frustrating, now with the clunk it has me worried, about 8 months ago I did change the isolator bolts and cleaned everything up pretty good.
HELP with ideas on what to try next would be appreciated.

Tony

 

Possible EGR problem on the cold start miss along with the other miss. As for the clunk, have you checked the universal joints?

 

Is there a way of checking the egr ? or maybe for $55 it might be just worth changing it out, not thought about checking the u joint I will have to look into that.

Tony

 

The way to check a EGR is to apply vacuum and if the engine doesn't stumble [no change in the running of the engine] the valve is not working properly. If the engine stumbles the EGR is ok.

 

Check Engine light came on this morning and I am popping a P0301 and P0316 if that is of any help.

Tony

 

That's a random miss and miss #1 code. What brand plugs, wires, and coil pack did you use?

 

I got all of them from the dealer, it was probably May that I changed them all out.

Tony

 

I changed number 1 wire with one of the ones I took off before and I took it for a test run and the stuttering seems to have stopped (well for now) this is a temp fix because I have done that before, does this give any clues, also the clunk only seems to happen when I get the stuttering.

Tony

 

And now the Check Engine light has gone out

Tony