328i lambda........ - BMW Forum

dudehog · 02-19-2009, 09:11 AM

hi again folks. i know some bmw's (for some daft reason) have 2 oxygen sensors, but, on my 328i touring is there only one sensor and if so where is it. 'tis being ecasive. crafty sensor

thanksdudes!!!

jeewing7 · 02-19-2009, 11:18 AM

There are two and they are both located on the exhaust header pipe. Refer to this diagram for exact location.

SHAHAB323IS · 02-19-2009, 11:22 AM

Quote:

Originally Posted by jeewing7

There are two and they are both located on the exhaust header pipe. Refer to this diagram for exact location.

328's have 4 02 sensors...

Shanew1983 · 02-19-2009, 02:49 PM

no they dont just the two like the diagram above, not sure if the E46's have more but the E36 328i only has two

johnnyBgood · 02-19-2009, 03:27 PM

Quote:

Originally Posted by Shanew1983

no they dont just the two like the diagram above, not sure if the E46's have more but the E36 328i only has two

The ones in the diagram are only the 2 pre-cat......there 2 more post cat....for a total of 4........

#15 & #16 in link below.....SHABHAB is 100% correct 328's have 4. 1 in each header....1 in each post cat pipe!

RealOEM.COM BMW E36 328i CATALYST/LAMBDA PROBE

SHAHAB323IS · 02-19-2009, 05:03 PM

Quote:

Originally Posted by Shanew1983

no they dont just the two like the diagram above, not sure if the E46's have more but the E36 328i only has two

This isn't my first rodeo buddy.

jmo69 · 02-19-2009, 08:26 PM

I wish US spec 328's only had 2! I'm not looking foreward to replacing all 4 at $100+ ea. when that time comes. I'm tempted to do the sparkplug antifouler mod to try and make them last longer.

johnnyBgood · 02-19-2009, 08:58 PM

U.S. spec 328's have 4 o2 sensors, 2 pre-cat & 2 post cat.....not so sure on euro-spec?

SHAHAB323IS · 02-19-2009, 09:11 PM

I never replaced the 02's on my car, worst case scenario your mpg drops a bit. I never noticed anything when mine went bad, check engine light was a little annoying but, oh well.

dudehog · 02-20-2009, 07:39 AM

well i can confirm that euro spec 328i's have 2 o2 sensors and us models 4. my dealership wanted £155.00 each (which is about $442.90 for both) but on ebay they were £50 each. so if anyone over there needs one (not sure how much they are on us ebay) have a look. it may be cheaper to buy one from here and ship it over.

actually, while i'm here question. on my tailpipe exit one side has a vertically pivoting butterfly valve. what's it for.? damn emissions regulations. didn't have this problem on my '79 trans am over here.heh heh

SHAHAB323IS · 02-20-2009, 09:07 AM

Quote:

Originally Posted by dudehog

well i can confirm that euro spec 328i's have 2 o2 sensors and us models 4. my dealership wanted £155.00 each (which is about $442.90 for both) but on ebay they were £50 each. so if anyone over there needs one (not sure how much they are on us ebay) have a look. it may be cheaper to buy one from here and ship it over.

actually, while i'm here question. on my tailpipe exit one side has a vertically pivoting butterfly valve. what's it for.? damn emissions regulations. didn't have this problem on my '79 trans am over here.heh heh

The butterfly valve, stays closed until a certain rpm, I think it's there for sound purposes (keep it quiet). It works via a vacuum hose. A lot of people stick a golf tee in the vacuum line so the valve will always be open.

jmo69 · 02-20-2009, 07:10 PM

^^^^^^+1 Sometimes referred to as the golf tee mod, just a little noisier.
I've done it myself.

basrite · 02-21-2009, 12:07 PM

hey guys!!!!

The valve is controlled by vacuum.. from memory it loses pressure about 2500rpm and starts opening. This creates less back pressure and more noise!!! So sounds sweet and creates more power.

Having a 320i.. i just opted for a triflow muffler.. sound all the time and another 20hp

j.

SHAHAB323IS · 02-22-2009, 10:56 AM

Quote:

Originally Posted by basrite

hey guys!!!!

The valve is controlled by vacuum.. from memory it loses pressure about 2500rpm and starts opening. This creates less back pressure and more noise!!! So sounds sweet and creates more power.

Having a 320i.. i just opted for a triflow muffler.. sound all the time and another 20hp

j.

The butterfly valve being open doesn't create more power. Well if .0001hp counts, then maybe.

20hp from a muffler isn't going to happen either.

basrite · 02-22-2009, 10:57 PM

it does when the inside of the old one was collapsing :P

The combo of cai helped too.