Xoutpost.com
Page 3 of 3 12 3
Show 200 post(s) from this thread on one page

Xoutpost.com (https://xoutpost.com/forums.php)
-   X5 (E53) Forum (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/)
-   -   DME: Trimming, oxygen sensor before cat., Bank 2 (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/110070-dme-trimming-oxygen-sensor-before-cat-bank-2-a.html)

andrewwynn 04-07-2019 02:39 PM
PS: if you don't have a tool with you to do adaptation reset, My original trick of unplug all O2, start the car a couple times, the plug them all back in seems to do the same function; even with my car running fairly lean (+7% long term), the error didn't come back for about 100 miles.

Fifty150hs 04-07-2019 10:00 PM
Quote:
Originally Posted by andrewwynn (Post 1159367)
I had same problem/ish and did the same and it worked for like six months and came back. I'm suspecting i now actually have a vacuum leak or bum MAF. I'll probably finally make/rent/buy a smoke tester and if no smoke, i'll swap MAF back from wife's car to see if there is a change.

I did notice in my case that six mo. ago when i originally did like above and swap MAF with wife, the fuel trims were more like +6, ±1% (short/long) and now there are both showing like +5 +7, so the computer is definitely seeing too much air or too little fuel.

what are your fuel trims now showing? if the long term is close to zero i think you're golden. I think i just acquired a new vacuum leak not the same problem returning.
Wouldn't a vacuum leak throw a code?

Fifty150hs 04-07-2019 10:04 PM
Quote:
Originally Posted by andrewwynn (Post 1159367)
I had same problem/ish and did the same and it worked for like six months and came back. I'm suspecting i now actually have a vacuum leak or bum MAF. I'll probably finally make/rent/buy a smoke tester and if no smoke, i'll swap MAF back from wife's car to see if there is a change.

I did notice in my case that six mo. ago when i originally did like above and swap MAF with wife, the fuel trims were more like +6, ±1% (short/long) and now there are both showing like +5 +7, so the computer is definitely seeing too much air or too little fuel.

what are your fuel trims now showing? if the long term is close to zero i think you're golden. I think i just acquired a new vacuum leak not the same problem returning.
Short terms are variable. -3 +/- to -4 +/- Long term steady at +7

andrewwynn 04-08-2019 03:05 AM
Quote:
Originally Posted by Fifty150hs (Post 1159393)
Wouldn't a vacuum leak throw a code?


Yep sure does. Im getting a code within 10-50 miles after reset. I think it's actually MAF or an intake leak.


Sent from my iPhone using Tapatalk Pro

andrewwynn 04-11-2019 09:27 AM
I think my lean codes mystery was solved last night when my fuel pump died. Hard failure just stopped while driving.

After it stalled I poked the fuel rail valve with a screwdriver and didn't even get a splurt.

The weird part is I thought I could hear the fuel pump hum but perhaps just too slow to generate any pressure.

Going with OEM brand this time. Knock off didn't last a year. I realized after I already had the knock off, so been mentally prepared for a while.

Funny thing is I actually thought to myself "if I don't have a vacuum leak, low fuel pressure will also cause a constant state of lean".


All times are GMT -4. The time now is 04:19 PM.
Page 3 of 3 12 3
Show 200 post(s) from this thread on one page

vBulletin, Copyright 2025, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.6.0
© 2017 Xoutpost.com. All rights reserved.