I just fixed a vacuum leak and the car sligtly vibrates at low rpms and I've been told to reset the parameters of the Ecu box. Is resetting the box a common thing to do? and is it something that requires the VAG? Ionly an OBD-II

 

pop your negative terminal off
unplug the ecu
reconnect terminal
turn key to on pos. you should have no Check engine light because it recognized no ecu
now disconnect terminal
.... and plug it back in.
connect terminal again.
turn key to on.
do a TBA .

keep in mind. that is what I DID. not time tested. i may have added a step not needed. but that how i did it
no more cel for me.

 

and turn your interior lights on when u disconnect the battery until they fade out completely. that way the ecu's memory is erased.

i did this on my friends 05.5 and it worked, but it won't work on my 98.5 for some reason. if it doesn't, just go to autozone and have them clear your codes. its the same thing

 

So I disconnected the negative cable but did not disconnect the ECU box. I thenturned on the interior light to discharge any capacitors. After 3 hours i connected the negative terminal.
Results:
no change at all in the way the car idles rough ( Cel is not on)
the radio was working fine w/o me having to put in the code which I thought was odd
My question is:
Do I need to disconnect the Ecu box eventho the battery is disconnected? And if so, where is the Ecu located?

 

this happens to my car whenever i get cel too. you can reset the ecu all you want, but the codes are still stored in the computer. clearing the codes will generally help. try clearning the codes then reseting.

oh and the ecu box is the black plastic box on front of the driver in the engine compartment. you would have to open the box (requires T-30 bit) if you wanted to disconnet the ecu. you may have to drill out the tamper proof screws as well. but you shouldn't have to o throug all that to fix this problem.

 

what does tba stand for

 

pop your negative terminal off