I need some help guys, I recently installed shorty headers on my 2004 f150 heritage xl 4.2 v6 5 speed 4x4. I just finished them and pulled the truck out and it runs horrible it chugs at idle almost like its not getting gas and it has a ticking noise coming from the side of the block like an exhaust leak but i checked the gasket and nothing am i missin somethin. I got the headers from redline

 

off hand I'd say that you pulled a vacuum line off or loosened a connection to a sensor during the exhaust work.

You've prolly already done it, but go back and carefully double check everything.

any codes tripped?

 

Theres a line runnin from the header near the down pipe that im not sure about i stoped at napa and got new wires and found a plug was on the wrong cylinder now i just have the exhaust leak and i put it on a scan tool and got 5 codes i think they are missfires

Po316

Po300

Po302

Po303

Po304

 

I put headers on my truck and didn't have any issues like this, so I'm lead to believe that these issues are not from the headers themselves, but something else you've done in the process. Maybe an absolutely massive leak could cause misfires, but I don't know.

What brand headers, what gaskets, what header bolts, etc. did you use?

 

The misfires i fixed i replaced the wires and made sure they were run right and it runs fine except for the exhaust leak they are redline shorty headers the gasket came with them as well as the bolts it sounds like its only on the drivers side and i removed and cleaned the block gasket and header and still leaks

 

Sorry, I thought you were still getting those codes and that Redline was a store, not the manufacturer of the headers.

You could try getting OEM Ford gaskets, like I did because the gaskets that came with mine fell apart right out of the package, but they're expensive. Some of the high-temp gasket-maker may help as well. Dorman (or Ford) replacement studs might be worth a shot too, and they're cheap enough to be worth trying. I may have very small leaks as well, even with new OEM gaskets and $100 locking header bolts. This is just one of the many lovely complications that come with aftermarket headers.

Keep in mind that once a gasket is blown, it is permanently ruined.

I assume these headers are regular steel and not stainless? Stainless is thinner and can "tick" a little bit, which I believe to be my potential "problem," but yours sounds like it's much worse than a little tick.

 

I think you did something to one of the O2s after the manifold. Those things are super sensitive. They are your air/fuel ratio sensors, if something is wrong with one of them an unbalanced reading will make it run bad.

http://www.mr2.com/TEXT/O2_Sensor.html

 

Yea at idle its a tick but when your actualy running it flutters real bad i think the headers are dna motoring for ford 4.2 97-04 heritage

 

Well I hope that ain't the issue. That would suck and be a big oopsie

 

I think the headers and down pipe may be sitting at an awkward angle thats what i will check first and then the welds on the headers themselves

 

Alright, I hope for the best.