Well last night after work I pulled the HKS air filter out and put the stock air filter back in. I then let the car idle in the driveway for 10 minutes...then 10 minutes more with the A/C on (a procedure I'd have to do with my old mach 1 so the ECU could "re-learn" the idle after a new mod).

The car now runs even better...better than the night before when I reflashed to the Cobb Stage 1 tune w/ the HKS air filter still installed. Idle is absolutely dead steady now when waiting at a light, power is smooth & steady all the way up to 5000 or so, and I haven't noticed any small backfires when upshifting. This weekend I'm going to try the Perrin tune again, but this time the stock air filter will be in place.

I really feel now that it was the HKS "Super Ultra Mega Deluxe" piece of crap air filter with it's non-pleated design that was most likely causing turbulent airflow past the MAF...causing all my problems.

Anybody want to buy a slightly used HKS air filter cheap?

 

Well i just got my AP. I drove around most of yesterday with the Cobb map inplace and noticed some rough idle. I loaded the Perrin map and I thought it felt better but I didn't drive it enough. I hope the idle issues go away tho.

 

I just put in the HKS filter w/ the Perrin Stage 1 map, drove for around 15min last night and it felt great...

 

I've noticed that the idle is a little funky for a couple of days after I flash a new tune. I also found that letting the car idle in the driveway for 10 minutes, then 10 more minutes with the A/C on seems to speed up the re-learning process of the ECU.

 

Just about the same thing happened with me when I first intalled the HKS air filter & downloaded the Perrin Stage 1 tune.

Then once the weather warmed up (we just had our first 90 degree day this year), I started to encounter problems. For the record I use nothing but Hess 93 octane gas bought at a high volume station. I like the Hess stations around here because they have separate hoses for each grade of gas.

 

OP you have WAY too many mods to be running the base stage maps. I certainly hope you have a boost gauge and wideband going since you have no idea what's going on.

The staged maps list explicitly what you can and can't have to be safe. On neither list is UICP or turbo inlet.

 

See this is what im talking about DarwinX. Im pretty sure those two mods are a no no.

Another thing is maybe your maf might be a bit more sensitive.

HKS’ high-performance Super Hybrid Filters are a direct replacement for OE panel filters when a factory airbox is required or preferred. Super Hybrid Filters features a 3-layer dry-type filter. The filter element is bonded to a flexible nylon frame and offers a price-friendly performance alternative to a full intake system.

http://www.hksusa.com/categories/?id=1915

Right from the product page.

I know someone runing one right now, with over 5k mI with the Perrin map with no issues.

 

I have talked to the guys at Cobb about running a UICP on the stage 1 (I run the 91 oct) tune and they said it was no problem.

I don't know about the turbo inlet though.

 

Im thinking the same thing, the UICP might be ok, but im combination with the turbo outlet pipe might create quite a bit more flow. And some signals are not crossing each other correctly and cousing the issues DarwinX is having.

 

Like I said.... everything EXCEPT your drop-in! I have a Perrin panel filter ONLY and no issues with the Perrin stage 1 map.

 

I'm running a Perrin turbo inlet, not outlet. The Perrin inlet is after the MAF and is the same diameter as stock.

 

Perrin told me as well that the UICP and Turbo inlet pipe, together with a drop-in air filter, was OK with their Stage 1 tune.

 

Of course they did to get you to buy the product.

Listen, you've got a computer controlling everything happening in your car. The stock tune, while crappy, is very, very, very safe and can deal with a lot of crap. The AP base maps are built for a very specific setup and have some safety built in, but if you don't match the setup *exactly* then you have absolutely zero room to be surprised when they don't work correctly.

The answer to your question is that you need to get to your desired mod level and then pony up for a custom tune that will match your specific vehicle.

Anything else you do will just be a waste of time and effort.