I have a 98 beetle. That has p0102 and p1564 it runs real rough idling but over 2000 it seems to smooth up. Some time dies at idle. It started running like this after my wife got out of it with it off and forgot to put the parking brake on it rolled down into a ditch. It busted the radiator witch I replace but now runs bad with those codes. The fuse 43 was poped I replaced it but it doesn't have but 1.29 v going to it with the key on. All the other fuses look good and have close to 12v going to them. I am lost on where to look on this. Any help will be appreciated
I had this problem awhile back with my 2002 NB 1.8t. The fix was the Water Coolant temperature sensor. It was registering -30 for the temperature forcing the fuel injection to put more fuel than necessary to keep the car running.
Difficulty was mostly when the car was starting up from a cold start, web humid weather. Once the car reaches operating temperature it would run fine.
Once the Water Coolant temperature sensor was replaced everything worked fine.
It's an easy fix. Just make sure the car sits after running for a 3-4 hours so that the antifreeze is not hot.
Then find the line that runs from the radiator to the engine block. There will be a clip in the middle that with a wire that contains the sensor. It is possible replace this sensor without removeing antifreeze. Just make sure you leave the radiator cap and overflow bottle cap on to retain vacuum to keep the antifreeze in. only a few drops will spill when the car is at room temperature.
Replace the sensor and with the new one and you'll be good.