So i will start from the beginning, last weekend i built a boost leak tester, and found huge leaks. The car would not hold any boost, so i fixed the basic ones, and now it will hold around 10 with small leaks, that i need more time to fix. well, i did not really compensate these leaks for boost. this weekend i just installed my new megan racing boost gauge. well when i took it out for a test run, it maxed it out, it goes to 30 pounds, and then the engine cut out . Well i turned down the boost controller, freaked out for a couple minutes that i was running the car at well over 30 pounds of boost for a week, and then got back to the real world. well i then tested it again. it spiked to around 26 pounds(where its tuned for), and then of course settled at around 20. well when i got to 4th gear, it decided to boost over 30 and max out the gauge again. i tried this a couple times, and sometimes it stayed around 26, sometimes it wanted to go to 30 or 30+. so i decided to turn the controller down about a half turn. i then took the car out again, and it would not boost past 12 pounds, actuator pressure i think. but then out of no where it boosted from 12 where it was locked to, to 26. so i turned the controller back up and now it stays around 26 in every gear but 4th. Please help guys what is going on, is my MBC toast, or what? or is my wastegate toast? also it pops hoses off like the PCV, and one of the hoses on the barbes on the back of the intake(where i found the huge leak with the tester earlier). The other thing i was thinking, some guy once told me that the Hallman MBCs have many different springs, and that i must have the heavy spring to be around 26 pounds. so did i disengage the spring and go to actuator pressure when i turned it down, and the lowest it goes is around 25 or 26 so when i turned it up a little bit it slightly engaged to the lowest setting?

Car details, stock turbo e85 1000 cc injectors big front mount intercooler tuned by mac autosports at 26 pounds, the car is also throwing a cel which i will get pulled tomo. probably lean or rich seeing the boost increase from the leak fixes.

 

you may be ok on e85. I would suggest doing a compression test to make sure everything is ok. Did you get tuned with the boost leaks?

 

Well. If he ^ is right then your tune is going to be off. Lol. You should prolly do a boost leak test b4 a tune. ZIP TIE all vacuum lines to keep them from blowing off. Even the one on the back of your gauge. Then get T-Bolt clamps. This should take care of all your leaks. Once this is done. Get tuned again. As far as your boost switch to a boost silanoid and let your ecu control your boost. Tephramod V7 is the shizznnitt.

 

Here was the code it threw - p0401 exhaust gas recirculation flow insuffictient rpm = 1714 ignition timing = 11 dgrees

 

and ya it was tuned with the leaks, i bought the car and it ran like crap so i immediately took it to get a tune, full well knowing the previous owner had tampered with it to make sure it was safe. the car still need a lot of work, and i will get it retuned when i get all the problems fixed(still has nasty leaks that need further inspection), cams and maybe a new turbo under it. hello summer job lol

 

I don't know what kind of an answer your looking for, but if you get all your leaks fixed then I'm guessing the po401 code will go away. Then if you get a retune you should be good to drive your car like you stole it. Not saying you would ever do that. haha