Ok so lets say im at a redlight and I take off, my boost levels go to 22psi which I have it set to but then it starts to decrease very rapidly to about 14 psi unitl I shift into the next gear then goes back to 22psi and drops again.. But then lets say that Im just riding around doing about 45 and i put it in 5th gear and floor it, it holds the 22psi all the way through fitfth. Sorry pretty much what Im saying is that when Im at low rpms and gun it the boost holds 22psi, but when im to driving and drop the gear and gun it, it stays 22psi for about 2 or 3 seconds and drops to 14psi. So far what Ive done to my car is 3"dp,fmic,apr chip, and a homade MBC. I did buy vag and It keeps getting a check engine light saying im running to lean! I was reading on some post and ppl are saying that there is no reason for me to go to a 4 bar fpr. Should I go ahead and just buy a 4bar? Do you think im starving for fuel at the top end, maybe thats why my boost isnt going like it should? Or could it be my homade MBC? If its both Ill buy the 4FPR, but what MBC should I go with? ECS is selling some for like $50.I just need some advice, the car has about 70k and the tbelt,waterpump etc has all been done!!! Im getting a nitrous wet kit for free so I was going to put that on but i wanted to fix my lean prob first. Just let me know thanks!!

 

check you maf sensor unplug it and drive with it see if that cures the problem

 

You have a vac leak or the mbc doesnt hold the boost well. Start off by taking out the mbc and just run the n75. If it runs normal.... well... you know. Do that and report back.

 

Ok Ill do that tom thanks...but doesnt the n75 only boost 18psi? How would I know if it will hold the 22psi? Im sure its the MBC!!!

 

It will go to w/e the chip is set (you say18psi) and then stay there unlike the mbc that you said drops to 14psi right after spiking