I swear to god, I have had this car 9 months with ZERO problems. I just had some kind members here help me out with the oil pressure switch situation saving me a ton of money instead of bringing it to Audi themselves. Now I have a new issue to deal with. I was driving fine after the oil pressure swith was installed, and NOW I was driving the car (after a AUDI OEM plug change) and the car in D at idle drops down to 4-500 RPMs, check engine light starts blinking, and I rev it a couple times, it stops, and is good to drive again (check engine stops blinking) I ran the car with a generic reader, and came up misfire #1,2,3,4,5,6,7,8!!!!!!!!!!!!!!!! 8 codes. I cleared it and waited drove for a while and it started stuttering again. I can't believe this. I just spent (oil sending unit, gasket for the unit, oil pressure switch and INSTALL on everything close to 500.00!!) Thats without the pugs and cleaning my filter. I noticed when changing the filter that it was dirty and not fully connected to the air intake tube, so I know SOME debris got in there, but again, this problem only started happening after the plug change and oil pressure change. changed the oil also. Now I have heard of the TPS going bad on these V8's and it's expensive to fix because its built intot he throttle body and I need a whole new unit not just a sensor (550 from Audi) The MAF is 200.00 from Audi. Does anyone have any suggestions on what this can be. I mean it's intemittent, not consistant. I love this car, but seems like I fix one thing and something else goes!

Misfires in all8 Cyl? I mean obviously its ONE thing wrong here cause those are the only codes I was throwing. I drive an 2005 S4 V8 for anyone that can answer me, it would be greatly appreciated. Thanks.

 

Look into the MAF, fouled plugs, make sure the sensors on top of the airbox are all connected tightly. A coil could be bad. could be a fuel issue. It's hard to tell. Lots of things can cause missfires.

 

Thanks, where would you start first? Do you think it could be a TPS in the throttle body? It is ONLY at idle that the car is missing. The coils look fine. Would the MAF be throwing thost types of codes?

 

The MAF would probably throw a lean code.

I test coils by switching them to a different cylinder, but you have a mis on all cyls.

There could be an electrical thing going on with the fuel pump. (more of a saab issue) but it happens.

have someone clear the codes and reset the adaptions.

 

Possible incorrectly gapped plugs causing the misfire?

Josh

 

Nah the plugs are pregapped Audi I thought of the gap already but they are pregapped. I just have a funny feeling it's either TPS or MAF> I am not familiar witht hese V*'s soooo used to American Powerplants. Fuel pump causing a mis?

 

yeah if the fuel pump is not sending a steady supply of fuel it would cause it to miss. Do you have any other codes other than the misfire codes? What about the CTS (Coolant Temp Sensor)? I don't know if those are prone to failing on your car though.

Josh

 

Its sounding like the TPS to me.

 

OK OK Thanks guys for the input. I have not had a chance to give the car over to Audi for the ultimate decision as tot he problem, but I think it's the TPS which SUCKS. It is built into the throttle body itself and they do not sell it seperately (which means a 550.00 part) I was driving the other day running an Evo on the street, and my throttle got stuck in WOT position. I hit the brakes and held them with the e handle and POP something poppoed under the hood, and car returned to normal, so I think it might be the TPS thats causing the misfire, especially when I am sitting at a light when the car is warmed up and the mis starts to happen (It gallops like the car is stalling out). I have needed the car and hoped I could get an exact before I purchased the MAF and the throttle body assembly, but the MIS is too hard to diagnose myself. Should this car have these issues at 60K? TPS? I mean seriously! To those of you V8 owners, have you had any of these types of issues with yours? Bad sensors and sucH? Throttle body? I mean I BABY this car. I run when its worth it, but there is nothign worthy of running. I was also reading another thread about the V8 compared to the BI turbo Stg 3 and I have done my fair share of running. Its not only the 1/4 times that matter here guys, its also the top end power, which I find that this V8 had no mid range power! If anyone has any other suggestions as to what my misfire issue or throttle issues are, please let me know! Thanks again guys.

 

try unpluging the throttle bottle for awhile and plug it back in.