I recently had a huge exhaust leak in my downpipe, and when my car would get over 10 lbs of boost, it would fart and sputter. I had the leak fixed and my car made it up to 15 lbs of boost before the farting and sputtering.

video:
http://www.fire-pixel.com/temp/sputter.mov

One thing that has happened that may be to blame is my Idle Air Control Valve stopped working properly so my car wouldn't idle. Once the temp was up it would idle extremely low (400-500rpm) and usually conk-out. to mask the problem until my new ICV shows up, i turned the screw on the throttle body out ~3 turns. now the idle is good when the car is warm and i'm waiting on my new ICV before i turn it back.

my question is, is changing the screw setting probably related to the sputtering and farting over 15 lbs of boost? my air/fuel ratio is right at around 15.2 while idling. i'll know once my new ICV is installed, but for right now i'm just looking for piece of mind.

Thanks!

 

installing new IAC Valve this weekend, i'll post the result

 

still sputtering, boost leak?

 

Did you mess with your TPS sensor? Eg: take it out of the throttle body?

 

try changing your plugs? had the same issue and it was sparkplugs

 

yes, had a misfire in cyl 1 and that was taken out during the trouble shooting.

 

Did you mark the TPS sensor when you took it out and put it back together the same way? The TPS sensor is calibrated to the throttlebody and changes values when it is moved left or right during mounting. If it isn't put back the same way, it will misread and give incorrect values to the ECU.

 

my mistake, after looking more closely at what a "TPS Sensor" is, we didn't take that off.

 

Then it might be your spark plugs, try changing those (as idriveanevo suggested). Make sure you have them gapped correctly.

 

will do, i'll post my results, thanks.

 

bad plug was the issue! I was using some Autolite XPs from Advanced Auto for one month. i installed them while i was troubleshooting a different issue, but now i threw some $2.00 NGKs in there and all is good! thanks for your posts!

 

No prob, glad it helped