Just got my car retuned with a base tune and the car was idling perfect.
After 5-6 pulls on a dyno and coming off it, the car starting idling lumpy (like a dirty idle in a rally car, 830-900rpm and little pops from the exhaust). Reverting the tune to the base and stock one did not help. I have checked the fuel pressure hose, cleaned out the throttle body, performed a boost leak test and my spark plugs are new. Yet these don't seem to fix the problem.

Any advice guys?

 

Isn't pop sounds an indicator that your running rich??

 

I am also having idle issues, but my issues come and go. Is your idle issue intermittent, or does it constantly do what you are describing?

 

It's constant

 

"Just got my car retuned with a base tune and the car was idling perfect."

You have mods on the car and you were getting tuned for them?

"Reverting the tune to the base and stock one did not help"

When the idle started acting badly, you reverted back to the stock tune to make sure it wasn't the tune?

 

Yes to both. With the base tune the car was idling fine. I took it to the dyno the day after for fine tuning, and after that it started idling lumpy. Reverting to the base tune did not help.

 

I have checked the fuel pressure hose, cleaned out the throttle body, performed a boost leak test and my spark plugs are new. I suspect it's the O2 sensor but I can't be sure.

 

I have weird idle issues and a P0134 code and suspect the O2 sensor as well. I have had a fuel pressure test, injectors flowed, fuel pump flowed, and changed out my FP relay.

I still need to check for an exhaust leak. I havent had a boost leak test done, but my LTFT's are good, and my idle issue comes and goes, so I don't suspect a leak.