My SS started surging under light throttle (cruising - no boost). Seems to run fine as soon as I start loading the motor. I noticed the AFR meter gets erradic when it surges. AFR will bounce between 12 to 17. As soon as I start to load the engine it stabalizes around 14. I'm suspecting a Mass Air Flow sensor issue with the K&N filter. I've heard that the oil from the filter can contaminate the wire in the MAF sensor. Going to see if I can clean it and put the stock air filter back on for a while. Anybody else have this issue?

 

Mine is doing some of that in reverse only.

 

See this and many other posts. You will probably have to remove the K&N. Mine is back in the box on the washroom floor...

https://www.chevyhhr.net/forums/show...t=27872&page=3

 

Turns out mine needs a new lower connector at the cold pipe, and if that's not enough it needs the turbo release valve too. So I'd say check the conectors, they just unplugged it and it doesen't surge in reverse now.

 

Huh, wuh? They disconnected the lower T-map on the Cold IC pipe?

The problem with K&N filters is that they are a "forever" filter and require cleaning and re-oiling. Too little oil and you suck particulate through the intake, too much oil and you fowl the MAF, or severely limit your air-intake.(think about breathing through a wet towel, had to do that once in a fire, your lungs get a little wet cough for a bit much like our motors).

A slightly larger filter will fix this. When I installed a K&N filter to the SS the "SS" kit was still a year from being released. K&N supplied me with a Cobalt filter in '08 and even before being tuned never threw a code. Subsequently.... The filter K&N supplied me with had one small quirk. the air-box lid is just a tad bit shallow, and there was a slight touching between the filter and lid.(thats why they supply you with a shiny lid thats a touch taller). The problem stemming from the K&N is in their pipe leading from the box to the intake not the filter, yes they made the pipe bigger to accomodate more flow but there is actually a drop in flow because of the diamater change, it doesn't take a rocket doctor to figure this one out. The ECM thinks there is a problem because its programed to work with....(stick stock part here).....and not (stick custom part here). My $.02 Just get a K&N filter, or a custom CAI and tune.

 

I had the same problem after installing a crazy steve hotside pipe. The problem was the rubber hose that connects to the intercooler. Problem solved with ZZP silicone hoses now on sale for $69. Apparently the hose kinks easily and can restrict air flow.

 

They replaced the lower tmap wiring and made a bracket for it to keep it from rubbing the ac condenser. Replaced the turbo release valve. All is running correctly again this thing is fun when running right.