Any CEL? If yes, was it flashing? My guess would be vac leak or a coil pack.

 

The check Engine light is on now, cant remember if its flashing but it was on, ill check later, it wasent on when it stalled out at auto zone and even when i kept trying to start it, but it is on after I get it towed to my house and put new plugs in it so ill run codes today, but it when I try to start it it sounds like it is almost ther and about to start but just wont,

 

Vacuum leak? My DV came loose one day and the car barely ran, if not stalled.

 

are you getting enough spark? it sounds like you're getting power but that may not be enough juice to fully ignite the fuel. also did you smell fuel through the spark plug hole when you changed them? the other thing is to check the MAF but none of the symptoms lead to it. the throttle position sensor is right on the throttle body. there should be a harness right on the sensor

 

Puled the codes today and I have misfire in cylinder 4, changed out coil packs or swapped 3 for for and still misfire so that rules out coil pack and the other code is Main Catalyst efficiency below threshold (bank 1) not all to sure what that means, been told by a few ppl that could be bad cat converter is that true any way to check and see if it is that thanks guys

 

yes it could be a bad cat. hit the cat with the soft side of your fist or palm and see if it rattles. if so it's definitely bad. but a bad cat shouldn't cause a misfire only on cylinder 4. have you tried swapping plug wires?

 

I swaped the coil packs from 3 to four and it still said misfire in cyl 4 but if this means any thing it was an oriellys tester not one of the ones shops have that prob tell everything so what you think about the misfire and could it be bad temp sensor

 

i would change all the coil packs

 

Where did all the intelligence go on this forum? If its a 99 1.8T it has a bad ICM (ignition control module) on top of the airbox. This has been talked about maybe 3,000 times in the past few years, does anyone search anymore?
Half way down the page http://www.ecstuning.com/Audi-B5_A4-...ine/Ignition/2

 

A bad ICM, would that cause my car to stall out like it did, and pucker and kinda start but just die after you keep on start. and would that throw Cylinder 4 misfire code and Main Cat Efficency Below Threshold (Bank 1) just trying to get as much advice as I can cause just not good at diegnouseing like some of yall are