1994 Grand Caravan MAP Code
bigj-dog
02-18-2008, 08:22 AM
My 1994 Grand Caravan's Check Engine light comes on after 15 minutes or so of driving. The codes that come up are 51 and 13. I'm assuming that 13 is related to 51. When I got the van it didn't start, somehow the MAP sensor was not allowing it to run, must've had some sort of short in it. Anyway, bought a new sensor and van started right up and ran fine, but after it warms all the way up, the light comes on. I checked the vacuum and it's around 18 inches, and drops and rises normally when you accelerate or decelerate. I grabbed another MAP sensor from a junkyard van and the light still comes on. Anyone have any ideas where to go next? If I were going to be driving it, I'd just leave it, but I'd like to sell it. Thanks for your time.
82Stang
02-19-2008, 06:09 PM
found on allpar.com
"51 Oxygen sensor stuck at lean position (Bob Lincoln wrote: may be tripped by a bad MAP sensor system causing a rich condition, and the O2 sensor trying to compensate. The O2 sensor may still be good. The MAP assembly consists of two pieces, the valve and the vacuum transducer (round plastic unit with cylinder on top and both electrical and vacuum connections) - If you get hot rough idle and stalling, especially on deceleration, accompanied by flooded engine and difficulty restarting, that can be a bad MAP sensor causing the O2 sensor to try to compensate. If you get poor cold driveability, stumbling and bucking, and acceptable warm driving with poor gas mileage (a drop of 10 mpg or more), that is usually the O2 sensor. [Webmaster note: MAP sensors seem to die regularly.] "
"51 Oxygen sensor stuck at lean position (Bob Lincoln wrote: may be tripped by a bad MAP sensor system causing a rich condition, and the O2 sensor trying to compensate. The O2 sensor may still be good. The MAP assembly consists of two pieces, the valve and the vacuum transducer (round plastic unit with cylinder on top and both electrical and vacuum connections) - If you get hot rough idle and stalling, especially on deceleration, accompanied by flooded engine and difficulty restarting, that can be a bad MAP sensor causing the O2 sensor to try to compensate. If you get poor cold driveability, stumbling and bucking, and acceptable warm driving with poor gas mileage (a drop of 10 mpg or more), that is usually the O2 sensor. [Webmaster note: MAP sensors seem to die regularly.] "
bigj-dog
02-20-2008, 02:50 PM
Thank you for the response. I'll pick up a new o2 sensor. It surely can't hurt the gas mileage any, as it gets about 13 right now. Will post back.
bigj-dog
02-24-2008, 03:53 PM
Changed the O2 Sensor, light hasn't come back on yet. I'll drive it to work this week and hopefully the mileage will come around, it can't get much worse. Thank you very much for the help.
82Stang
02-24-2008, 04:42 PM
Changed the O2 Sensor, light hasn't come back on yet. I'll drive it to work this week and hopefully the mileage will come around, it can't get much worse. Thank you very much for the help.
Glad it worked out for you....so far!
O2 sensors are usually not too cheap so always better to be sure before going parts replacing. Can get costly.
Post back if light comes back on.
Good luck.
Glad it worked out for you....so far!
O2 sensors are usually not too cheap so always better to be sure before going parts replacing. Can get costly.
Post back if light comes back on.
Good luck.
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