2010 V6 Ford Sport Trac and OBD check engine codes

[Yvette52]

I have had a full tuneup done on my sport Trac but periodically the check engine light comes on and the OBD code says I have a cylinder misfiring. When I say full tune up that included spark plugs, wires, coil, air filter, etc. the truck does not run any different when the light comes on so is the service department at Ford missing something?

 

[J_C]

Welcome to the forum!

Obviously they are missing something. What is the specific OBD2 code?

I'd want a scan tool capable of live data, and start by looking at long term fuel trims. Maybe you have a vac leak, or dirty MAF sensor or IAC. Does the light come on in any particular situation, like only at idle or under significant load? Did it start happening immediately after the tuneup? If it was a shop that did the work, I'd complain to them a little more to fix the problem, assuming it did not have this problem before the tuneup, or did it already?

Just for the heck of it, I'd check that the spark plug wires are fully seated, on both the coil and the plug end. I'd also make sure none are routed too close to the exhaust manifold and might have burnt so now shorting out intermittently.