Maybe?
Just called the NJ shop - Hogan Tire put the wrong spark plugs in, causing the engine computer to start throwing error codes and shut itself down. They'll swap the plugs and test drive it tomorrow, and hopefully I can get back on the road. Another $200 for parts and labor, but if it turns a pile of scrap into a working car, it's money well spent.
In summary, Hogan Tire in Waltham can kiss my half-Colombian ass.
Update: Going from what the mechanic said, and doing some poking around on the interwebs, it sounds like the engine that Chrysler used in the Neons is very picky about the spark plugs that it uses. Using the wrong type of plugs, or not installing them *just so*, will cause the tips of the plugs (which generate the sparks) to erode much, much faster than they are normally supposed to--as in a matter of weeks, instead of years. And when they do erode, it causes rough idling and cylinder misfires. Which sounds alarmingly similar to what my car was doing, a few weeks after new not-quite-OEM plugs were put in. So, *crosses fingers* this sounds like the issue. And it means that I'm willing to chalk Hogan's goof up to ignorance, not stupidity.
In summary, Hogan Tire in Waltham can kiss my half-Colombian ass.
Update: Going from what the mechanic said, and doing some poking around on the interwebs, it sounds like the engine that Chrysler used in the Neons is very picky about the spark plugs that it uses. Using the wrong type of plugs, or not installing them *just so*, will cause the tips of the plugs (which generate the sparks) to erode much, much faster than they are normally supposed to--as in a matter of weeks, instead of years. And when they do erode, it causes rough idling and cylinder misfires. Which sounds alarmingly similar to what my car was doing, a few weeks after new not-quite-OEM plugs were put in. So, *crosses fingers* this sounds like the issue. And it means that I'm willing to chalk Hogan's goof up to ignorance, not stupidity.