edbeard1

A couple of weeks ago, my 02 Gt developed a loping idle, and died a couple of times. I got it home, had an odor of fuel, no leaks. Thought about the mass air flow meter, pulled it and cleaned it thoroughly with MAF cleaner. Closed the hood, took it for a ride, seemed to be better, except the idle didn't want to come down right away.

Got it home, popped the hood, saw that I had not plugged the sensor back in, plugged it in and back to fluctuating idle.

I read somewhere, on one of the Mustang forums, if the car ran better with the sensor unplugged it was the sensor. Well that is apparently not true, at least in my case.

I received the obdII check tool that I ordered, ran the codes, too many to list, however the MAF sensor was the first one listed. Replaced it yesterday, cleared the codes, went for a 30 mile ride, back to crappy idle. Checked the codes, rt and lft bank too lean. Now I realize that the MAF unplugged had caused all of those codes, including the ones I am still getting.

Yes I do feel kinda dumb for not clearing the codes before seeing what it looked like with everything hooked up.

This car has 78k on it, with 6k on a new motor. I ran seafoam through it a week ago. And it is a new MAF sensor. And I disconnected the battery for an hour, before I took it for the ride today.

Any input will be very much appreciated.

cliffyk

Here are the possible causes,

Check the easy things first, intake leaks after the MAF and exhaust leaks around the front O2 sensors...

Hangwire

You should NEVER, EVER seafoam a motor with 6k on it. When you unplug your maf and run without it trips a code. Clear the code and plug the MAF back in and it wont be a problem you DIDN'T need to replace that MAF.

cliffyk

Seafoam is the preeminent snake-oil. It was introduced in the early 50s for use with marine engines (that's the "sea" part) that were typically run cold, stored for the winter tied up to a dock, and often poorly maintained.

So unless you have no thermostat, leave your car tied up to a dock for the winter, or have never performed even basic engine maintenance for 10s of thousands of miles, all it will do (if you are lucky) is nothing; at the worst it will create all sorts problems that one would expect from dumping kerosene into a gasoline engine...