Rich out-of-boost after muffler delete

streetzlegend · 11-03-2009, 10:35 AM

So, I removed my muffler and put a straight 3" pipe, its awesome, i gained 3psi of boost, etc...

The issue is, my idle AFR is dropping to the low 11's. Usually with muffler on its always at 14's. After I go for a drive, and say I get into boost and then drive normal again, once i come to a stop or idle AFR is back in the 14's. Can someone explains this to me? Can it be that after I get on the gas, the turbo starts spinning and basically keeps spinning freely since there is no restriction in turbine outlet causing for more air to be flowing into the manifold at idle, possible?

Should I just give it time so the ECU can get used to the new maf readings?

For those not familiar with my setup, I dont have o2 sensors. My ecu runs open loop all the time and I manually tune it myself via EU.

mywhitewolf · 11-03-2009, 06:26 PM

possibly faulty fuel pressure regulator? if you boosted more than you normally do and then it broke it could just be the extra psi that it saw that broke it?

streetzlegend · 11-04-2009, 08:40 AM

Problem seems to be fixed, I put in the stock injectors and car idles perfectly a/f stays solid. When i took off the 440cc RC injectors one of the o-rings was actually blocking the tip of the injector (I had doubled up on the o-rings, big mistake). btw regulator is perfect, fuel pressure is solid.