P0506

1st post- Great Forum! I’ve searched but can’t seem to come across anything definitive that tells me what the problem is and how to solve the problem.

I have a 05 GT with most of the usual bolt-on mods, running a SCT2 tuner. I will do a retune about once every oil change, not changing anything, just applying the same tune that’s in the car already. Suddenly out of nowhere I’m getting a P0506 code and there’s not enough displayed in the tuner screen for me to know exactly what is going on. I’ve had this tuner for a while now and have retuned the car many times since then with no ill effects.

If anyone can help with what this means or where I can find more information on this code I will be grateful.

Thanks in advance-

P0506 Idle Control System RPM Lower Than Expected


Do you have an aftermarket throttle body? That's an awfully wierd code to come up especially with no previous trouble. By the way no need to keep uploading your tune...not good to keep erasing and reloading your PCM.

Thanks Tommyroc, I haven't changed the TB it's the factory one. I'll clean it good today and see if that helps.

In the event any one was wondering. I cleaned the TB last Friday after work and it hasn't thrown a code since then. I can't believe I let the TB get so bad it was throwing a code!

How many miles on the car?

46k and I do preventative maintenance during every oil change, cleaning the TB is one of those. It makes me wonder about the quality of gas, this came on quick.

This happened to me, but it was also having trouble idling at the right speed. I took my TB off and it was filthy. It came from the C&L intake I put on. Apperently, the filter from C&L comes with a lot of oil and it gunked up my TB. I cleaned it and haven't had any problems since.

If it had enough oil to gunk up your throttle body, imagine what it did to your mass air sensor. Might want to look into some of the spray can cleaner for it.

What kinda spray would you use for that cleanup..??? What about a little "Sea Foam"..??

For the TB use a Spray TB cleaner not a carb cleaner, I use B-12.
For M.A.S. use a Spray Electronic cleaner, I use CRC.

Haven't run any Sea-Foam through the S197 but I have in the old SN-95 and it pumped out a lot of smoke for a long time but it did seem to help. So far I've been using Lucas products in the S197.