2g Check Engine Light Problem..

[BiG_DeE]

okay so i recently bought the car.. and it had 5 check engine lights, all air fuel related but when i used the scanner it said that they wernt bad just not working properly and the car ran really rich the car is pretty stock other then a boost gauge, safc2, and a walbro 255 fuel pump that the guy before me put into it. the safc isnt tunned and well heres the weird thing that happend..

was gonna install my car stereo yesterday and i unplugged battery which reset the ecu and so i had to go do something so i plugged it back in started the car at first it started REALLY rough, then it got going like normal but the CEL's wernt on.. and the car was idoling at 1500 and i drove it probably 50 miles and the cel didnt come back on. so is it possible that its fixed?? I was thinking maybe the BISS screw wasnt set right or something?? also.. anyone know how to run wires to the doors?? for speakers! haha

 

[Mr Peepers]

An AFPR should be your next step, with that 255 you are overrunning your stock one. That could be the reason it is running so rich/poorly, but if you just bought it you should also do maintenance such as timing, boost leak test etc. When you are checking the timing and get it into spec with the timing plug grounded out, that's when you adjust your BISS. Also, if you don't know when the last time the timing belt was changed, do it now, bent valves aren't cheap.

 

[AK_4g63t]

Your check engine light will come and go when certain DTC's are thrown and will stay when other codes are thrown. When you disconnected the battery you reset your ECU and cleared all the codes. Sometimes it takes a code weeks to show back up. Keep driving it for a while and if the light comes back on THEN check for codes. Then since you've cleared your ECU's memory you'll know which are the current problems you have and you can look those up and find the rout to take to find the reason for that Diagnostic Trouble Code. Also, just because the CEL isn't on doesn't mean there aren't any codes. You can pull from your "history" past dtc's, even the reason your CEL came on at startup. If you wait too long though, your car it will delete that certain DTC after it the problem doesn't reoccur xxx times in a row.
The reason your car may be running right is because your vehicle "learned" how to run correctly with the sensors data and a blank memory. I would also highly reccomend a AFPR, the 255 is overloading your stock one.
-Donny
*anyone correct me if I'm wrong here. I'm a General Motors mechanic and I'm new to the Mistubishi vehicles.