I put in the K & N filter in a 2008 SS and the next day the check engine light came on with a air flow sensor code. I replaced the air flow sensor and reset the code. In less than 20 miles the check engine light is back on. Haven't had a chance to read the code yet but assuming the code is the same. The car runs fine unless I try to get on it and the boost never goes above zero. I really don't want to give the dealership any money so I am open for any ideas. Thanks

 

our SS's don't always agree with the K&N filters...give these threads a read
https://www.chevyhhr.net/forums/problems-service-repairs-42/k-n-intake-causing-check-engine-light-come-43560/

https://www.chevyhhr.net/forums/ss-specific-service-issues-repairs-61/p0101-question-i-know-not-another-one-42896/

https://www.chevyhhr.net/forums/2-0l-performance-tech-46/what-my-chances-getting-code-k-n-filter-46411/

or search it...there are probably 100 threads on this

 

I have seen this before. Put your stock air filter back in clear the codes and see if the code returns

 

It would appear that I am one of the unlucky few that has problems with the filter. That is a shame. I will try a couple of the ideas that were in the threads that I read, but it looks like the old, boring factory filter is the best fix. Thanks for the quick responses to my question.

 

Nothing wrong with those "old, boring factory filters".
In fact, they probably flow as good as the K&N. GM did a pretty good job of the design of the stock SS airbox and filter combo.

 

That's right, I think the K&N replacement filters are over rated and over priced. There's been numerous test/dyno showing loss in hp with K&N over stock filters. I'm not sure about HHRs but in others I've heard.

 

Is it just the filter or did you get the cold air pipe also? I've had one in mine for a couple of years now. The air filter should not impair the engine to produce boost, make sure a boost pipe has not blown off... Just a thought.

 

Same thing happen to my 08 SS. When I put the filter by itself I got no boost after a few miles. When I bought the full intake it started working fine and no codes. But my MPGs went down to 14 so I put the stock system back on and sold it.

 

An aftermarket air filter could indeed impair the engines ability to produce boost. If the MAF reads abnormal airflow it will cut timing, boost, ect.. to protect itself.

I guess I am one of the lucky ones. I dropped in a k&n filter only in my first SS (09 auto) with no problems or codes. Also dropped in k&n filter only in my current SS (2010 5-sp) with no problems or codes as well.