Short story version...Forgot a part during re-assembly and on the re-do broke another part which took me from a $12 repair to a $392 repair.
Long story version.....
Had some bad luck working on the 'dirty emissions spewing' vw. It has the urea injection on the exhaust and it has had a engine code for a bad temperature sensor on that tank. The temp sensor is supposed to control when the heater comes on to keep the urea from freezing at about 20*. Dealer wants $1100 to fix it, the complete replacement heater kit cost about $400 but since it is only the sensor that is bad on mine (according to the fault code) I figured I could try a $12 10k ohm thermistor before dropping more $$.
This is a common enough issue that there are some detailed instructions on the heater replacement on the VW forum. Went through the disassembly of the bumper, tailights, dropped the tank and replaced only the sensor, tested it out and all was good. Then reassembled the tank and bumper and tail lights which in all took about 3 hours.
Was feelin' real good about saving some big $$ then I noticed the styrofoam spacer that fits over the tank sitting on the garage floor.
OK, frustrating do-over but it has to be done....took it all apart again, much quicker this time since i had practice, put the styrofoam in place and was getting the tank bolted back to the underside of the car when the fragile plastic nozzle the pump tubing connects to snaps off. I'm SCREWED!
No way to fix it, have to order a whole pump assembly for $380 because of a stupid fragile plastic nipple. Others on the vw forum had this same issue and I thought I was being careful with it but obviously not careful enough.
I'm trying to rationalize the extra cost is still cheaper than the dealer had quoted at $1100 but it still makes me mad my $12 fix was undone.