so recently ive actually ripped my cutoff off my car from "dodging" a raised manhole cover.. when that happened my wideband has been showing that i have been running alot leaner then i normally do cruising (been higher then 17) i took a look at it and saw that my downpipe actually cracked (which is now welded) and the place in which the wastegate actuator was held by off the radiator side of the turbo came off (ran 0 boost for a bit, but had really good gas milage lol) well now im still running really lean and i cant pinpoint the problem, ive checked my narrowbands and their good but i have been getting codes for misfire/egr and whatever o2 hotside (code) is.. if anyone can give some more ideas, that would be great.. oh i got codes 171 and 137 i believe

 

must have a exhaust leak before the wideband

 

Finding the leak:
Strap a vacuum cleaners exhaust air tight to the tail pipe. Make sure your in a clean environment so you dont contaminate the chamber with debris. With engine at TDC and TB closed, turn on the vacuum so the exhaust duct becomes pressurized slightly. Take your premaid solution of soap water (1tbs dishsoap/12oz h2O) and spray over everything upstream WBO2 sensor. Bubbles will develop over leaking areas.

After finding leak it is a good idea to pull the #4 (overlapped at tdc) plug and place a strong vac source on that with TB open to suck out anything that may have gotten in there.

Or you can just try to find it the old way