2003 Grand Marquis problems

[MadMan]

Originally Posted by Adam

but I thought those code readers were hundreds of dollars

The little ones have been getting steadily cheaper. If you want a real scanner that can do everything, $2k minimum.

Here's a cheapie basic one
This one is still decently priced, but will also let you look at live sensor data. I have a slightly-higher model one of these (model 6001) that I use daily at my shop for quick checks.

I would definitely recommend getting one with data stream capability. Not all cars have it in the data, I don't think yours does, but some have a misfire counter for each cylinder in the data. Still, when other problems arise, data is very helpful. Without codes and data, it's kind of like working with your eyes closed. And I don't know if you have emissions tests up there, but any of these little scanners will tell you if it's passing (I/M readiness). Also, it's always good to have one of these around to check on family's and friends' cars.

They have some other ones that are just a nub you plug into the car, and download an app on your phone to read it. Haven't yet tried any of those. Also I was just at Harbor Freight the other day and I peeked at the scanners there, I think there was a half-ass decent one for $45 or so.