Started my truck up friday morning after it had been sittingfor 4 days without being started, check engine comes on and stays on, I remove TST COMP box, restart truck, still have an CEL, take up to TST, weget 2 codes, P0602 and P0237,(ECM timing and MAP sensor, respectively) clear the codes, no box, start truck, no CEL driving around town on errands, after about the 3rd stop, when i refired for the 3rd time after coming out of walmart(maybe 30-40 minutes), started truck, CEL back on. Take back to TST, same 2 codes, clear them, drive it home, turned it on and off 4-5 times, let it run for 10 minutes, shut it off, waited 15-20 minutes, started again, NO CEL so im thinking its a lose wire, check connections, nothing seemed lose or corroded, repeated the same starting procedure and still no CEL so im thinking its okay, so it sat all day without being fired, went to start it to go to work at 9pm EST and guess what CEL back on?!! What could be causing it to trip the same codes with no box? DTRB shows low voltage on MAP sensor as the P0237 code and the P0602 code comes up as an ECM incomplete date and timing code. Could the MAP sensor be going out?

I did noticed that lately that it seemed to be fueling differently, like not to fuel until my mechanical boost showed almost 20 lbs which is 4times higher then what the comp should start fueling and its not smoking as much under load but sometimes itd be okay and run normal. Truck is running, and we did hook an injection pump tester to the electronics of the VP to be safe and it came back good. we also tested the TST box to ensure it was not the cause and it is not, the box is funtioninf perfectly. Any other tips? This map sensor is the orginal i believe with 250k miles and the good Lord only knows how many times its had boxes plugged in and out of it. ive lost count.

 

pull all the connections and clean them with some lectramotive type spray then use some dialectric goo and reinstall

 

that works or you can just unplug you map sensor but it will make you smoke more...

 

try removing and cleaning the map sensor too. they can get all gummed up

 

anyone know where i can get a socket locally big enough to remove it?

 

sears?

 

almost any auto parts store should have it

 

autozone and yeah any auto parts store probably...