I posted this on the engine management and tuning section also but I don't think it gets as much traffic as this one so here it goes.

Okay so lastnight I got a new cold air intake in from ebay. I was attempting to install it when one of the two tiny metal tubes broke off that are supposed to have a vaccuum line from the head attached to it. So I install the stock intake back on and everything is perfectly normal looking MAF is plugged in, the Rubber Dry Sealer plug is in all the way and instead of the stock intake box I decided to throw the new air filter I have on there. I go out and drive around and my car starts bucking and surging like CRAZY, it literally almost threw me into the windshield. So something is definitely wrong, I take off the cold air filter and leave it the way I had been driving it for about two days now with just the MAF and no filter. It still does it.

I took it to Auto Zone and had the codes read and it's throwing a PO139 code, which is just my O2 sensor on my exhaust, which is fine, because I have a 3" turbo back exhaust. It's also throwing a PO234 code, which is an overboost condition. How the hell would me putting on a stock intake create an overboost condition? The car after I drive it for a second starts idling sporadically and it goes between like 600-1,000 rpms and is loping at times. If I give it gas it just builds boost and doesn't accelerate.. WHAT IS THE ISSUE!?!?!? HELP!

I have an SAFC2 and a wideband hooked up and at idle the wideband goes between bottoms out at 11 and then goes all the way up to pegging out the gauge. My friend did the tuning on my SAFC and it has ran great for about a week now with no issues so I highly doubt it's the tune but it may need a re-tune, perhaps something I did caused the A/F Ratio to go ****ing nuts and is causing the ECU to over compensate fuel or something.. Any help or tips would be great thanks!

 

try the stock air box. post a link to the ebay intake you got.

 

ok I will have to post the link later tonight. I'm at work until 10pm CST and I won't be able to get it until then.

 

Driving your car around with nothing protecting the MAF is not too smart. They arent cheap and the honeycomb is big enough to let something through to damage your turbo.

Ditch your filter and put the stock airbox back on. Ditch the SAFC and get a real tune.

 

well there's a fish net filter over it, and it's only been like that for a couple days. My stock airbox won't fit because of my 50mm Tial BOV welded onto the upper IC pipe. The SAFC2 is perfect for what I'm doing besides I have had several friends of mine running 11s and 10s in their evo's with nothing but an SAFC...

 

Do you still have the solenoid attached?


OT: Classy SN.

 

What purpose does a Tial BOV serve on practically stock Evo? I'd love to see proof of those Evo's running 10's on a SAFC alone for engine management.

 

Because Tial Sounds ****ING AWESOME! It's not all ricey like those HKS blow off valves. It sounds like your choking a bird everytime you let off the gas.

 

lol I want it to be my license plates haha. How cool would that be on a white evo?

 

if you got the hks replica from ebay, a friend of mine was using the same one and had the same problems you have. we took care of it by replacing the mushroom filter to a k&n, hope this helps

 

Well I had my friend come pick up the car from me while I was at work yesterday and he did a little tuning on the SAFC, replaced the spark plugs for the second time in a week and reset the ECU. This seemed to fix the issues and I guess my boost gauge wasn't correct either. I got a new boost gauge lastnight and upped the boost to 22psi, and I guess it was only on 15-16psi before. Now the car feels much faster and much smoother. However it still hits boost cut or whatever it is in 4th gear if I'm trying to build boost at a lower RPM like under 4,000rpms... I'm not sure why maybe it's because I'm on stock IC piping and it's trying to pull in too much air in those little stock pipes...

 

You're running too lean. Like I said before, get a real tune, not a bandaid.

 

Get ECUFlash , A wideband o2 ,and a Tactrix Cable, It takes a lot to learn how to tune, but my VIII has no knock at 25 psi, thats important. BTW, are you Venting that BOV to atmosphere? Please say no. Running lean with a stock timing map is a bad day, its going to run and sputter and knock.