pbrules-I found the thread you were talking about and I took my laptop out to the car to match up the pics with my car and what's in that space under my hood looks different than what's in your pics. Could that be because I have a 99 1.8 and you have a 2001? I don't know, but I don't see that part in the spot its in, in your pictures.

Now I'm focusing on the clogged injector possibility and trying to swap the injectors around like randomaudiguy suggests, then taking it for a rescan to see if the misfire moves to a different cylinder. You have to bear with me here, I used to wrench on my own cars a lot when I was younger, but its been a while, I've never worked on an Audi before and I didn't bring many of my tools with me when I moved out-of-state recently. I'm attaching a pic of what I assume is the part I need to remove to get at the injectors. If you look at the pic, I'm assuming that the long, shiny metal tube in the middle of the pic, that looks like it feeds fuel to the injectors, needs to be removed first. It has 2 hex bolts near either end, I was going to loosen those to lift up the tube to get at the actual injectors to swap them-correct? Is there anything else special that I need to do in there to get at and remove the injectors?

Assuming I can get the injectors swapped and if then a rescan would show the misfire moving to a different cylinder, what would I then do to get the bad one unclogged? I've never had much faith in those bottles of cleaner you pour in the gas tank, what else could I do to clean the injector?

Thanks again for EVERYONE'S help here, I would be in a real bind if it wasn't for all the help I'm getting!

 

Ya, that's what AZ charged me, it was actually I think $52 or so, plus tax it came to $58 and some change! When they pulled it up on their computer, they asked if I had a 3 blade or a 4 blade, the 4 blade was a lot cheaper, I think $34, but I had the 3 blade coil. Hopefully it won't matter anyway, because now its running rough again, so I think I'll end up taking the coil back anyway!

 

The new ones are way cheaper, the old ones are about 60 bucks, give or take a few bucks depending where you got it.

BT, do a search for a Seafoam Treatment. It's not guaranteed to unclog an injector, but it sure as hell is better than the cheap bottle stuff you put in a gas tank.

Yes, the injectors are on the fuel rail. Undo the electrical connections on each, unscrew the 2 screws, and the whole thing pops out with all the injectors still attached to the rail. I've never actually swapped injectors before, so I'm not exactly sure how the injector comes out of the fuel rail.

Replace the spark plugs too. If you don't know when the last time they were replaced, then they are overdue. They are only a couple bucks each, the cheap ones are fine. Many members here change them every other, or every third oil change. The 1.8T eats plugs like candy.

These are just a couple inexpensive ideas to try and get you through. I agree with the others that once you can afford it, you need to really get in there and diagnose what's going on. The seafoam is about 7-8 bucks a can (you'll need 2 cans), the plugs are a couple bucks each, and swapping injectors is free.

The chances of the misfire killing your cat in such a short time is not very likely, but it's not impossible.

 

I ran out of time to work on the car today (and daylight, I don't have a lighted garage to work in either) so here's my plan for tomorrow: I'm going to try removing the fuel rail like you said and taking the whole thing out, it sounds like it comes out in one piece. Then hopefully I can figure out how to disconnect and swap the injector from misfiring cylinder #3 with another one and see if the misfire moves to that cylinder. If that's the case, I'm still not quite sure where to go from there as far as unclogging the injector. I found one write-up that talked about soaking the injector in some injector cleaner.

I'm thinking that the clogged injector explanation makes sense, since I now know its not the coil pack and after I cleared my codes last night, the 2 new codes that came back were the the P0303 indicating the cylinder 3 misfire, along with the P1300 low fuel etc. code. Also, from my research, I saw it mentioned several times about injectors getting clogged after people run out of gas. My A4 has the common gas gauge issue, where it works above 1/2 tank but doesn't work below 1/2 tank and in the last year, I did run out of gas a couple of times, not real recently, but maybe that helped clog the injector.

While I'm doing the injector work, I'll also pick up some Seafoam and new plugs just to cover those bases, too.

Anyone have any ideas about what I should do to unclog the injector if that does turn out to be a problem?

 

I'd advise replacing the injector. You can do the seafoam just to try it, but if you find a faulty injector i would replace it. After you get the rail out, just pull the injector out, the rail sandwiches it to the block. Take care with the O-rings.

 

Yes, I suppose it would make sense just to get a new injector if that's the problem, only problem for me is getting one locally. There's a AutoZone and Advanced Auto Parts near me, I looked on their websites for fuel injectors, AutoZone has 2 choices on the website, 1 for $180 and 1 for $135 (wtf-$180 for 1 injector?!!!) and they both are shipped only, they don't have them at the store. Advance shows 2 choices, 1 new for $99, 1 remanufactured for $50, it says to "call the store" about the remanufactured one, they don't say its out of stock, but not that they have it, either. The store is closed now, so I'll have to call in the morning to see if they have one or not. If I can't find one in stock locally, I'll have to try cleaning it, I really can't wait around for one to get shipped to me.

I also found this diy on replacing injectors, looks helpful:

http://www.a4mods.com/index.php?page...injectors.html

 

It's as easy as that, yep. Though i just yank the injectors out, that'll bleed the fuel pressure real fast too

 

I took out the injector rail and pulled the injectors off from cylinders #1 and #3 (#3 was the one that was misfiring) when I looked at the injectors, I saw that on #3, there's like a plastic ring around the bottom of the injector, the end that actually sprays the gas. On #3, this ring had cracked and part of it was gone. I don't know how this could have happened, but something's definitely not right. #1 looked fine. I swapped them and went back to the parts store, but someone else was using the scanner. I asked the guy to look up and see if they had an injector in stock, they didn't and have to order them, it would take until Thursday to get it. So, now I'm going to look on the net and see what I can order and just for kicks, I guess I'll call the stealership tomorrow and see if they have one and what crazy price they charge for one.

I'm still wondering if I have a vacuum leak, too due to the rough idle, but I guess I'll have to do some more investigating. I'm also still wondering why the problem comes and goes as fire as the misfire while I'm driving. It ran smooth today for the 8 miles I drove, although the rough idle and dying when I start it up is always there.

 

All the symptoms you are having happened to me before I fixed that suction pump. I know you said you couldn't find it but try looking again or maybe someone could chime in because I'm not sure how different the 99 layout is compared to 01. I was having trouble starting once it started, it would work for a few miles as you said then it would try to die. I got misfire codes from the engine trying to keep itself at idle but it would bog down and die.

 

I'll look again and do some searching on the net about that suction pump, hopefully I can find it!