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Car running lean

ChrisTSI

Ready to race!
Location
Canada
Okay so the car will be taken to mechanics this Wednesday, but I am hostage in my own house, and would like to try and fix it myself lol. . Issue came relevant when I filled up gas at a station up north , felt sloppy on the highway drive home.
Things I’ve done:
-change sparks and re gap(old plugs shown signs of lean)
-take off JB4 , cold air intake

The cars fuel trim levels fall flat on their face at 4K to redline mostly 3-6th gear feels super sloppy and car backfires when it’s running lean. As well as the car idles messed up but only sometimes, I can still limp it around town under 80km/hr but I prefer not to.... no cel light or codes. Anyone got suggestions besides pump/injector
 

MeltedSolid

Autocross Newbie
Location
San Francisco Bay Area
Car(s)
'15 Golf, e36 328i
Have you logged this with the JB4? It'd be interesting to see just how lean you are running. Also, while my issue is probably unrelated, I was able to use the JB4 to decrease boost everywhere and that made me run richer and safer. To do that I set 1500rpm to just over 10psi and set it to 5 psi for everything after that, so now my car runs around 10-15psi.
That might be a good thing to try out.
 

ChrisTSI

Ready to race!
Location
Canada
Have you logged this with the JB4? It'd be interesting to see just how lean you are running. Also, while my issue is probably unrelated, I was able to use the JB4 to decrease boost everywhere and that made me run richer and safer. To do that I set 1500rpm to just over 10psi and set it to 5 psi for everything after that, so now my car runs around 10-15psi.
That might be a good thing to try out.

With JB4 disconnected and completely removed same thing.
 

MeltedSolid

Autocross Newbie
Location
San Francisco Bay Area
Car(s)
'15 Golf, e36 328i
Oh yea, same problem as in the other thread. So the car thinks it's running rich, which is causing it to run lean? In the log the AFR looks fine, maybe a bit jumpy but not unreasonable values, so this would lead me to believe failing O2 sensor? Maybe?
 

ChrisTSI

Ready to race!
Location
Canada
Oh yea, same problem as in the other thread. So the car thinks it's running rich, which is causing it to run lean? In the log the AFR looks fine, maybe a bit jumpy but not unreasonable values, so this would lead me to believe failing O2 sensor? Maybe?

Maybe would the cause be because of the afr wire tap? For the sensor to fail?
 

Ironshade

Go Kart Newbie
Location
Atlanta Ga
Whooaa, car going nuts from look at ign 2345. Interesting.. i’ve heard of a car locally wear the cam down for hpfp.. but he was at 130k miles
 

ChrisTSI

Ready to race!
Location
Canada
cars at VW dealership, its in warranty but they wont touch car under warranty cause of downpipe so i told them to fix it without warranty lol. Service manager is nice and is helping me at a discounted rate... i got 02 sensor too rich CEL this morning (cars been parked for 4-5 days). So lets wait till tomorrows phone call.
 
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