Running rich and flat spot in acceleration

[foshoitsbmo]

I've had my '04 unmodded Lightning for about six months now, and I've noticed a couple issues with it. It seems to be running very rich, you can most definitely smell gas if you stand by the exhaust when you start it up, and it continues to have that smell at idle.
I've also noticed a flat spot (like a hesitation) in the acceleration, especially under WOT, between 3000-4000 RPM (haven't been able to peg down exactly where yet).

Any chance these two issues are related? I have the L serviced regularly, and at my last service they suggested I replace my air filter as it was starting to get pretty dirty. Could a clogged air filter be the cause of this?

Thanks for the help

 

[wydopnthrtl]

You really need to hook up a wideband a/f gage in order to answer your questions.

IMO.. it could be a slow 02 sensor (or both) causing the richness. A dirty air filter would not cause it to run rich becuase the MAF sensor is what's telling the PCM how much is entering the engine.

As fas as the flat spot... I again wonder if it has a "tune" in the PCM / computer. Could also be the fuel pump resister not letting the pumps go into high flow mode. (or what ever it's called)

IMO the best thing to do is hook up a wideband a/f gage and go from there.

Rich