yeah i have done alot of research and a couple of people have had the same symptoms but no one knows what to do... i wasnt talking about the pre cat sensor i was talking about the coolant temp sensor i just replaced it cause alot of people were saying that could be why it wasnt starting and my coolant temp gauge wasnt reading right...but i used a $6.99 duralast one from autozone. so i was wondering if maybe its cause i didnt use an OEM one. sorry im not freaking out i just havent had any responses and i dont know what to do seeing i know how much ill pay at a shop to just find out whats wrong. any help if appreciated and if none comes i wont be bad ill still be on audi forums 10 hours a day ha

 

also its kinda jittery when driving like almost a studder

 

okay so i just replaced my fpr, fuel pump relay, fuel pump and put an OEM bosch coolant temp sensor in and still having trouble starting. anyone have any other ideas?

 

I am having the same problem. The Audi dealer told me that if I bought an aftermarket fuel pump, that it may not have a chack valve, and that the fuel system could be bleeding down when it is turned off. I have an aftermarket fuel pump, and a new fuel filter. I am researching too, let me know any solutions, as will I.

 

@patrixx006 I had a bad coolant temperature sensor and it was showing 130 all the time but this didn't give me any trouble when starting the car. You probably have problems with the ignition system or fuel system.

 

This morning driving to work I smelt gas inside the car. The fumes were still flowing inside the car on my drive home. I did catch a whiff of gas while walking behind the car too. What am I looking at here?

 

It could be the rubber seal above your fuel pump. Open your trunk, remove the metal cover and look at your fuel pump seal.

 

hey the coolant temp sensor you replaced where was it located....please let me know asap
and what color are the wires

 

I don't know if this will help, but it fixed my problem, and know its nice to see a fix on a thread. I replaced the fuel pump, fuel pump relay, and fuel filter. None of these fixed my problem. I payed the big bucks and went to Audi. Turns out it was the ecm relay under the hood drivers side under the wiper inside the ecu box.It was like $40. Once I put the relay in(myself, Audi wanted $125 labor), no more isssues. Easy 5 min replacement. I did post this fix somewhere, but didn't see it here so thought I would add it.