Over the past month or so I've been running Perrin's Stage 1 map with the mod's in my signature, and I've experienced slight back fires when upshifting, slight boggin off the line, and the occasional funky idle while waiting for a light...as if I was running super rich or something....inside of the exhaust tips were black as coal, and the best city mileage I've seen is 19 mpg. So as an experiment, last night I reflashed to the Cobb Stage 1 map (still using my HKS drop in air filter).

Idle is rock steady now, no back fires, and no bogging off the line. car feels more peppy and the power comes on way smoother.

Does anyone know if Perrin has updated their Stage 1 lately? Could it be the HKS air filter? Dirty MAF?

 

I tried both on my stock setup & the COBB map is far more stable.

 

Pretty sure the issue is everything other than your drop-in filter!

 

The reason I mentioned the HKS air filter as a potenial issue is the fact that it's not a "dry" filter. Perhapes some of the oil got on the MAF sensor or something.

 

Definitely is drop in filter! There is no doubt!
I asked Perrin about Drop in filter or intakes they said don't do it!
They are so clear about it..
Go back with Perrin map and install your stuck air filter, you will see it works great.
Intakes or drop in filter could cause over boost and bye bye to your evo! Unless there is a map for it..

 

The people at Perrin said a drop in air filter is fine with their tune.

As a matter of fact, it even states on the Perrin map notes that a drop in air filter is OK.

 

Well he told me is not OK at all!
Please show me where it say drop in is OK!
Any prove?

 

uh.. ive read in numerous threads that its perfectly fine to have a drop-in filter with the Perrin map, but not so much for the Cobb map....

 

Every car reacts a little bit different.

 

perrin may have said not to run the drop in at a later date. at first cobb made no mention of whether the drop in was good or bad until people ran into issues. i tried running the k&n drop in not too long ago with the perrin map in warm weather and i didn't like that i had knock retard values showing up any time i spooled the turbo considerably.

i would switch to the oem filter and see what happens. if no change then contact perrin or consider a custom tune for your mods.

i did notice that the car does subjectively run differently with the perrin tune. the cobb is much smoother like stock. with the perrin map the engine has a low toned growl to it.

 

What gas are you runing. Maybe your getting some bad gas, if the problem is recent. If using cheap gas, go and try good quality 93 oct for a few tanks see if it clears it up. Also call Perrin and tell them what's going on, maybe one of your mods aka the UICP or the Turbo inlet are causing the problems. I was told by Perrin that the HKS drop is and a catback is fine with their st1 map.

Oh and the HKS drop in filter is a dry filter, i dont know what HKS drop in filter for the 10 is wet!

 

Before I installed cobb ap and after I had bogging off the line, funky idle, and exhaust tips and rear of the car black as coal.
As for the backfires, I noticed them like crazy after I put the perrin exhaust on. Maybe they were always there and are now more noticeable?

 

+1, I tried works and perrin panel filters. Both were not worth the headache with cobb map and without.

 

If I could show you the display screen on my AccessPort when downloading the Perrin Stage 1 map, it states that a drop in air filter is "OK".

 

Good to know. I thought it was a "wet" filter because of the description:

"HKS high-performance Super Filters are a direct replacement for OE panel filters when a factory airbox is required or preferred. Super Filters feature the same 2-layer wet-type, polyurethane material as in the Super Mega Flow. The filter element is bonded to a flexible nylon frame and offers a price-friendly performance alternative to a full intake system."