08 S5 In need of some help...
 

Quick background check on the car ,

I picked it up about two months ago used at 53k miles. Had a pre-purchase inspection done on a car, and the tech noted that the intake was loose and was potentially throwing a ton of codes on the ECU. There were 3 intermittent misfires...

I test drove the car and as soon as I hit 4.4k rpm the cel started blinking , then went back to normal. I figured that it could potentially be something minor since it shut back off so I didn't mind it too much...

Either way, I drove the car all the way home from Penn - Michigan , without issues. When the weather cleared up and I pulled it out of storage, I took it for a quick spin....at 4.4k rpm the CEL started blinking , then went to solid.

At this point I figured that it would be smart going into the dealership...

Dealer recommended manual carbon cleaning, as well as plugs and all coils to be replaced. Since the car was out of warrenty it turned out being something I had to pay for, but since the 55k mile service entailed plugs anyhow, I figured why not.

Had everything done, and it went smoothly. Dealer advised that after repair the misfires were still happening intermittently. He suggested that I replace all fuel injectors at this point as well....over 2 thousand for those...I said I will give the car a few days to feel it out before I decide on anything.

Either way , after the dealers the car felt noticably stronger...however it still throws the CEL at 4.4k RPM and at times the EPC accompanies it at times as well.

I'm really hesistant on replacing the fuel injectors, specifically because I think that the coils and plugs were a waste to begin with, ( I saw the old parts on the tray and they all still looked fairly good, besides I know how dealers work by now...)

Judging from the symptoms , is it just me or does this look like something that could potentially be caused by an airflow issue...maybe a loose vac line ? ???


Any help is appriciated!!!!!!!!!!

OP
 

I am fairly new to Audi's but I do know my other cars. Yes a vac leak can cause it.....if something else is happening at 4.4k rpms that is pulling more vac. I dont see fuel injectors, plugs, or coils being a problem unless the car is misfiring or you can physically feel it sputter/jump. Go to a diff dealership or have someone hook up a vag-com to your car so you can actually read the codes it is throwing. Any dealership would have done this first and it will help dramatically eliminate problems.

4.4k RPM sounds like about time for the intake runner flaps to move. I'm pretty sure if you do a bit more searching, you might be able to find more information on the issue, where something that controls the flaps breaks.