Need a DIY for vacuum leak testing

wren57 · 02-01-2013, 08:27 PM

I am throwing lean codes p0171 and p0174. I imagine there is a vacuum leak somewhere although I can't hear one. Is there a DIY for a smoke vacuum test? I can't locate any whistles and also I tightened the clamps downstream of the MAP sensor. Car is back to 100% stock.

Rickygst · 02-01-2013, 10:15 PM

Those codes, I believe are the 29e0 & 29e1. It may not be a vacuum leak. It maybe air getting in somewhere. My car is having the 29e1 code and I haven't figure out the cause yet. How many miles on your car? How does is drive?

wren57 · 02-02-2013, 12:28 AM

90k miles. It drives really well, but if I get above 4k rpm I get a half engine light. Still runs fine after that tho.

NTXE92 · 02-02-2013, 02:30 AM

Just spray some brake cleaner on different areas and listen for change in RPM. If you still can't find it you can go to guitar center and buy one of those cheap smoke machines.

02-01-2013, 08:27 PM	#1
wren57 Roll Tide 591 Rep 2,346 Posts Drives: 335i Join Date: Jul 2010 Location: St Louis iTrader: (10)	Need a DIY for vacuum leak testing I am throwing lean codes p0171 and p0174. I imagine there is a vacuum leak somewhere although I can't hear one. Is there a DIY for a smoke vacuum test? I can't locate any whistles and also I tightened the clamps downstream of the MAP sensor. Car is back to 100% stock.
	Appreciate 0 Tweet Quote

02-01-2013, 10:15 PM	#2
Rickygst Second Lieutenant 19 Rep 260 Posts Drives: 335i Join Date: Jun 2010 Location: Atlanta iTrader: (5)	Those codes, I believe are the 29e0 & 29e1. It may not be a vacuum leak. It maybe air getting in somewhere. My car is having the 29e1 code and I haven't figure out the cause yet. How many miles on your car? How does is drive?
	Appreciate 0 Quote

02-02-2013, 12:28 AM	#3
wren57 Roll Tide 591 Rep 2,346 Posts Drives: 335i Join Date: Jul 2010 Location: St Louis iTrader: (10)	90k miles. It drives really well, but if I get above 4k rpm I get a half engine light. Still runs fine after that tho.
	Appreciate 0 Quote

02-02-2013, 02:30 AM	#4
NTXE92 Enlisted Member 0 Rep 36 Posts Drives: 2009 335i Join Date: Jan 2013 Location: Plano iTrader: (0)	Just spray some brake cleaner on different areas and listen for change in RPM. If you still can't find it you can go to guitar center and buy one of those cheap smoke machines.
	Appreciate 0 Quote