I have a 2002 Dodge Grand Caravan with a 3.3 flex motor. whenever I start climbing to high altitudes like in the mountains, the motor starts sputtering and backfiring and losing power. I have changed the computer, map sensor, and throttle position sensor with no luck. Anybody out there experiencing the same problem?
what was the reasoning behind changing each one of those parts?
are the plugs and wires in really good condition? (changed recently)
you should scan your van and see if there are any codes. See if there are any p0300 series codes. lean or rich codes. Then see if you can find someplace that you can drive the vehicle with the scanner on when it acts up. It could be either a fuel problem, running too lean or it could be a secondary ignition problem.
Look at your fuel trims when it's acting up. Are they adding fuel? Does the injector pulse width go way up? (starving for fuel)
check for excessive back pressure in the exhaust.
crank or cam sensor codes? Bad sensor, sensor connection, wiring rubbing through anywhere?