Can someone tell me why I got this code in my 99TA?
Code PO303: Cylinder number 3 misfire detected

This is what happens:

I can start up the car at any time, after it has been sitting over a day, or longer and it is fine. No problems. But when I drive somewhere, turn it off, go in, be it getting gas, Walmart, grovery store, anything less than 24 hours it happens-I get in, crank it up, start to drive and get a really bad hesitation, stumbling. Yesterday was the first time it gave me an SES light. It never blinked at me though. (This has been going on about a month, I have had the car since last July, and the only mod has been EGR/AIR deletion and a lid. And it has been properly tuned for them.)

But the hesitation always goes away after a minute or so. And it has never given me a code. But it always happens right after I start it up after a short stop. Like when it is hot, or normal operating temp. But yesterday was the first time I seen a SES.

Here is another fact: On the way home last night, the light went off. I read that when that happens, the car sees it as the problem has stopped. I NEVER get the hesitation or *misfire* any other time. Just when I start up, and leave from my destination, and only for a minute. Though while that light was on, it didn't feel as smooth. I was also told that the exhaust looked really rich when it happened. My husband was behind me when it happened yesterday, and said it looked like I was getting on it really hard, and it looked really rich.

I bought an Actron scantool, and it gave me code PO303. I erased the code, and will wait to see what happens. I just want to know what causes misfires? Is something else happening that it causing it? The car has 45k miles on it, and is an A4 car.

Sorry this is long, I just wanted to be informative. I REALLY hope someone can help me out.

THANKS!!!!

 

Takes 3 things to make a fire air, fuel, and spark.
My guess is that it's the injector for that cylinder sticking open. Maybe try running some good injector cleaner thru the gas tank. You could swap the injector with one from another cylinder and see if the miss follows the injector.

 

But what is causing the injector to stick open? And why wouldn't it give a code for the injector? I am just full of questions about it.
It is a perfectly good car w/ no real mods. And why does it only happen after I drive somewhere, get out, take care of business, get back in, and then it happen?

I thought about plugs, but isn't 45k a little early for them? Thank you for your help I will try some heavy duty injector cleaner

Anyone else?