High Idle and P0505 after cold air intake install

MadeinSweden1 · Post by **MadeinSweden1** » 24 Jun 2020, 14:32

So I have finally reached stage 0 and started with the add ons. The new cat and exhaust really made the naturally aspirated engine a joy to drive again, but I decided to complete the setup with a K and N cold air intake. The K and N 57i series induction.

Immediately after installation of this K and N CAI my idle went form 950 rpm to about 1300, plus or minus 100. When I first start the car it hovers at around 1000 and once it warms up its back to 1300 +/-. It soon threw PO505 idle air control. I began troubleshooting this and replaced the IAC two times and even spliced the connector wire with a new control harness to ensure electrical integrity. I thoroughly cleaned the IAC housing. I finished troubleshooting by replacing all new hoses attached to the IAC and air intake hose just for good luck. (I did install a 960 tb plate the same day, but have rechecked my work to make sure it rests fully closed).

I am still getting the code, and my idle is still high, but other than that the car does ride fine once it gets going. I called K and N customer service today and they said that the i series inductions kits were designed for UK regulations. I had never heard of this, as there are no indications that this happens a lot with these air filters based on customer service reports. He said to take it to a tuner to have them sort it out.
What can I do to tame this high idle without having to go to a shop?

Thanks in advance!
-Shane R.

Post by **misha** » 24 Jun 2020, 15:45

Did you installed a throttle body gasket?

MadeinSweden1 · Post by **MadeinSweden1** » 24 Jun 2020, 15:48

I did put a new one on because the old one was decayed away. Although I do remember the new gasket "popping" around a lot as I began to tighten down the throttle body bolts.

Post by **misha** » 24 Jun 2020, 15:51

It doesn't seal well...that's why you have high idle.Engine is sucking "false" and unmetered air.
Did you re-connect flame trap flange and hose on it?
Also...check that ribbed hose for air induction between maf and throttle body is tight and have no leaks.

Why that MAF sits upside down?

MadeinSweden1 · Post by **MadeinSweden1** » 24 Jun 2020, 16:04

I will definitely reexamine the gasket because it was a sketchy fit, it didn't want to stay flush until it was tightened down, maybe it was crimped little.
Where is the flame trap flange located again, Is that where the PCV system runs? I believe I reconnected it but am not aware of that part name. I do know that the hose that runs from the front of the car that was originally connected to the top of the stock air box is now resting. I wasn't sure if I was supposed to seal off this extra hose.
Thanks for the reminder to check the induction between maf and tb because that was a beast to initially get together.

Post by **misha** » 24 Jun 2020, 16:19

Flame trap flange also have a seal (o-ring) which prevents vacuum leaks between MAF and throttle body.

It's a bayonet style mounting.You can't remove lower side plastic adapter from throttle body,on which you mount lower ribbed air hose,without releasing flame trap flange.There is also a hose attached to it which is a part of PCV system.

Original ribbed hose which goes from stock airbox and MAF goes directly to plastic adapter which then goes onto throttle body.
On that adapter is a bayonet style flame trap flange.
How do you mean that it goes from the front of the car?

That plastic hose is going to a lower side of stock airbox,NOT upper,providing fresh air to airbox.

crlande · Post by **crlande** » 24 Jun 2020, 17:02

Why not put the OEM air box back?

Post by **abscate** » 25 Jun 2020, 04:40

That open hose is your unmetered air and this high idle

MadeinSweden1 · Post by **MadeinSweden1** » 25 Jun 2020, 06:47

OK, I had a feeling that the hose (to the left of the cold air intake hose) which is still open could be causing a misbalance. I was under the impression the " more air to the system the better". I will close that off after work today and update this.
Thanks!

Post by **misha** » 25 Jun 2020, 08:33

What hose you guys are talking about?
SAS pump hose which is attached on the upper half of stock airbox cover?
If so....you will soon have SAS code .
If you block it...air pump will blow it when it activates.
Your car is equipped with SAS system...so you will need to find the way to connect it on new style filter.
In the meanwhile...get back your stock airbox.