I just bought a 2003 Vue from Carmax: 2. 2l 4cyl 5-speed manual. It needed some work before I got it (valve replacement I think, code was P0302 cylinder misfire). Now it is reporting P1516 and sometimes P1515 (throttle position related), and it is enforcing the Reduced Power mode. It drives well enough to limp in to the dealer for my Monday appointment but that's it. I don't really know what I'm doing diagnosis-wise, but I know a couple of things:
1. Throttle plate opens fine by hand, and springs back closed when released.
2. My OBDII scanner (ScanGauge II) reports a change in throttle position when I move the throttle plate by hand.
3. The scanner does not report a change in throttle position when the accelerator is pressed, whether the engine is running or not.
4. Throttle plate flutters quickly a few times when the engine is started.
5. The voltage on some wire connected to the top of the throttle changes in the 3-5 volt range relative to ground when the accelerator pedal is pressed.
6. Idle is very rough.
7. Forgot to mention this all began when I stalled the car right after starting it by being careless with the clutch. Twice in a row. After that it wouldn't start at all until the next morning, when the trouble codes started appearing.
I couldn't find any TSBs that seemed relevant, not that I know where to look or how to tell if they're relevant.
I am wondering if I need to back out of this deal (two major mechanical problems in two weeks?). Any thoughts on whether this car will be fine once this is repaired, or am I doomed to repeated service visits if I keep this thing? I should still have a day or two to back out under Carmax's refund policy. But I like the car. . .