I've seen one or two mentions that some think the disabled learn down feature on the GMTU allows a K&N filter lightly oiled to be use without throwing a CEL but I haven't read 1st hand reports and I though the GMTU kept the learn down on the HHR. I know my previous cars would learn the airflow just fine and never had a CEL. I didn't know they threw regular CEL's until I got an HHR.

Any GMTU guys have success with the K&N?

 

I have had the K&N kit with the oiled filter on mine with the GMTU since 2010 and never had 1 CEL.

 

The whole CAI kit not just the filter?

 

I have the GMTU and a drop in K&N filter and never have had a code pop up. I have also read the reports of people having problems. I would assume that they get a code because they oil the filter to much and it gets on the MAF sensor.

 

Thanks. I'm getting tired of the paper filter and it not having it replaced due to cost as often as I'd clean my own. I may try the K&N on this car

 

I didn't have any problems with my K&N until I removed my airbox lid...It sounds amazing if you do... So I run a paper filter...There is not a noticeable difference in power with either filter

 

i have the complete kit on my SS with the GMTU and no issues or codes
been on at least a year so far...

 

Well this is the only vehicle I have ever had that I did not have a K&N so I just bit the bullet and ordered one. I'm going to clean it as soon as I get it since I do know they are over oiled sometimes from the factory and I'll just lightly oil it.