D-Rock

Hey i have 2007 f150 fx4 and my engine is a little shakey qhen stoped at a light but qhen in park smooth as ice??

Wwebster12

I just picked up an actron reader to help chase down a no code misfire. Found out #4 was the culprit. I moved the COP to another cylinder and reset the data. Another test drive showed cyl 4 was the problem (misfire didn't move with the COP). Installing a new plug tomorrow.

I'd recommend getting a code reader with mode 6 capabilities. Its been a headache saver for me.

D-Rock

Even with no check engine light ? I have no warning lights or anything. And honestly havent had any real issues with my truck.

Wwebster12

The link below helped me tremendously. No code misfire.

4x4Fun

Yes, you can have misfires without truck error codes. I have had that too and the aftermarket COPs, that I had used with no issue for around a year were the issue. I put in the old COPs and everything was fine again.

Ecobuilder

If you have an android device (phone,tablet, chromebook) get yourself the TorquePro app and an ELM bluetooth reader.

Cheap (~$25) and puts a lot of info regarding your truck into your hands.

It will allow you to see which cylinder(s) are misfiring and if there are any pending error codes.

ShirBlackspots

Something I've been curious about is how does the computer know precisely which cylinder is misfiring when it doesn't have a sensor per cylinder and records things per bank?

redfishtd

One-- it looks for the crank boost when that cyl is supposed to add torque . It also looks at the cop coil collapse kick coming back at it .
Just because you don't have any codes is not Legitimate claim of nothing wrong . Misfire have thresholds to set a cel otherwise they would be a real nuisance. Damage to cats can be underway , if you can feel it and it has other symptoms you know its not right . That's why you are here being proactive before something gets worse .
That's why there is a mode six to look at raw computer counts per cyl towards setting a cel . Torque pro is really cheap . 5$ /old android phone/cheap bluetooth reader amazon . There are many fixes here. This engine is very sensitive about its ignition circuit .