Green_Bandit

iTrader: (25)

Set up: Turboed with FMU

I'm throwing codes p0171 - System To Lean (Bank 1) & P0135 - Front O2 Sensor Heater Circuit Failure

I've replaced my first O2 sensor thinking that may be it but no go...

Its been a while since the conditions started but its like the topic says.

The idle bounces from 600-800 while in park and only in park.

As far as misfires, there are none in 1st WOT, in second WOT the misfires start.

I'm pretty sure the two issues are related but I can't find the root.

From reading other threads I think it may be a vacume line but I only touched very few. Those were on the side of the IM to connect my FMU and on the front of the IM to connect a vacum for my BOV. I don't think I messed with anything else.


I'm stumped on what to do next. Could you guys help me out?

Thanks!

ThunderOZ

iTrader: (26)

Do you have a wideband? Do you know if the FMU is still working correctly? Also check the vacuum hose for the fpr. Mine had similar issues and I found a small hole in the vac line...

4g94T

iTrader: (18)

If its misfiring under WOT it'll give a CEL for that. It's p0401, p0402, etc, the last number being the cylinder.

What spark plugs are you using? Along with injectors and engine management?

Green_Bandit

iTrader: (25)

Yeah, but I can hear it misfiring. :/ NGK BKR7E Iridium Spark Plugs - Turbo plugs with stock injectors with a Vortech FMU

ThunderOZ

iTrader: (26)

Have you checked to see if any codes are there? It may be one of the injectors not performing correctly.

Green_Bandit

iTrader: (25)

Got the codes today. Im still throwing p0171 - System To Lean (Bank 1) and I have a misfire on Cylinder 3.

I've been a little suspect of my FMU. It never gave me any reason to doubt it but I just don't trust it. When I get some time (probly Thursday ) I'm going to check the lines on it and pull plug #3. I'll probly also change back to my stockspark wires since a squirrel decided to "taste" my Magnecores a while back.

I can't help but thinking I don't have a vacume hose set up right or a hole in one but that would be too easy. Where you you have the vacume for your BOV tapped to?

No Wideband BTW...

5ynth3t1c

iTrader: (6)

If you change the plugs and still get the misfire code then you should check the coil packs. I had stuttering and misfires and that was my problem.

TouringBubble

iTrader: (2)

Check for an exhaust leak before the front O2.

*02Lancer*

iTrader: (3)

my car is a n/a still and just intake and echaust i have the same problem my car has 112k on it and stock injectors i did an Oscilloscope test and injector number 3 is failing. and it was getting pretty bad and i had the same codes i replaced the front o2 and it helped a little but still misfired really bad i would check your injector's if you could it might and if they good, the coils and wires are good,and fuel i would do a noid test on it to make sure your injector's are getting the signal to fire good luck with it.

Green_Bandit

iTrader: (25)

Pulled Codes again tonight... No more P0175 Cool But I'm still getting bank 1 too lean.

I pulled second and third plugs...
#2


#2 Top


#3


#3 Top



I went ahead and bought some new pluds and ran into another problem. They didnt stock NGK BR7E's so I ended up getting BKR5E-11 V-powers. Those are supposed to be cold plugs like the 7E's.

Would those be a safe replacement for the 7E's?

More info on the problem though, Now it seems as when I get into boost it's missfiring. When I pass boost threshold, I can expect them.

Would a bad coilpack on cyl #2 effect the spark on #3?

ThunderOZ

iTrader: (26)

Well doesn't the coil pack on cyc 2 also provide spark to cyc 3?

Green_Bandit

iTrader: (25)

It does. If it was a bad coil pack would #2 and #3 be bad, but if it was a bad wire only #3 would be going out right?

What do you think about the plugs?

4g94T

iTrader: (18)

Are those one step colder plugs?
I'm using the NGK BKR6EIX plugs, already gapped to 0.30"
Never looking back!

ThunderOZ

iTrader: (26)

Are the plug boots in good condition? I had similar problems with #2 until I changed the boots(or wires I guess you could call them).

Green_Bandit

iTrader: (25)

No the wires are not in great condition. A while ago a squirrel chewed on both of my wires but they ran fine. I always was looking to replace them but since they never flubbed up it wasnt high on the "to-do".

But I'm changing them back to stock right now and I just happened to find 2 extra BR7E's just laying around from the build last year so I'm putting those in now. I'll see whaat happends...

Those other plugs the BKR5E-11 are supposed to be one-step colder plugs but I've never heard anyone mention them so I was kinda unsure. I'll keep those NGK BKR6EIX's in mind though.