HELP! BAD idle

**sti4now** · 11-07-2008 10:54 AM

So i noticed a crack on the vacuum line for the diverter valve/BOV so I fixed it, but I had to unplug the sensor right in front of it where the Y pipe is. I guess it is either the TPS or maybe the map sensor? I drove the car and it was very rich because I forgot to plug that sensor back in. I immediatly put it back on started the car back up but it does not sound smooth at all at idle almost like piston clap through the exhaust, but I think its just extremely rich. Could the APR chip have gone into a valet mode or the ecu went into limp mode? HELP please

**highPSI-S4** · 11-07-2008 11:00 AM

You meen the sensor on top of the TBB? I would try reseting the ECU by disconnecting the Battery terminal for 5mins or so and plug it back in and see how it runs. do you have a boost gauge? How much HG. is it showing?

Sounds like something else is not connected.

**sti4now** · 11-07-2008 11:02 AM

18 at idle, but I think it sounds this way because I need to reset the battery. BTW the CEL is on since that sensor was unplugged

**ThirdStrike** · 11-07-2008 11:04 AM

an unplugged MAP sensor would probably cause limp mode. like he said disconnect your battery
if you are 18HG in vacuum thats probably a healthy system(no leaks)

**sti4now** · 11-07-2008 11:15 AM

I did the CEL went away but its sounds like its misfiring and is very rich

**AudiSportB5S4** · 11-07-2008 11:23 AM

check for boost leaks.... typically they say a good vacuum idle is between 19-21 in HG. So you're short somewhere... Do you know how to pressure test the car ? If so try to pressure test. Check the fitting of the TBB and also check the fitting of that map sensor thats on top where you forgot to plug it back in. Make sure its all the way inside the TBB