bluehawk2

iTrader: (74)

I'm working on a friends car and we have a problem with the passenger side of the engine. He noticed a problem when the car started to sputter a little and finally a code for system lean bank 2 came on.

I looked at the ltft's and the O2 voltage and the ltft on just B2 periodically up to 25%. O2 voltage is low on that side as well.

I thought this would be a problem with the o2 sensor, so I swapped sides with the o2 sensors............no change. I swapped the o2 extensions to the other side............no change


I noticed an exhaust leak around the collector, so I fixed that and still nothing changed.


We replaced the plugs and all four plugs on the passenger side are black.....super rich.

I thought this might have been a problem with the fuel injectors, but not all four on that side.........besides the plugs show it is running rich instead of lean on that side.


It reads lean on B2 just like an exhaust leak, but there is no leak.


We have checked for vacuum leaks, but didn't find anything




Where else do I need to look? The car still has the AIR on it.........I don't know if that could affect anything just on the passenger side.


Any help will be appreciated


thanks

bluehawk2

iTrader: (74)

Forgot to ad that at idle both B1 and B2 ltft's are reasonable.........around 4%. They aren't exactly balanced, but close.

When I touch the throttle to rev it up B2 immediatly shoots straight up to atleast 15%, but when you let off of the gas B2 ltft goes back down to normal and as soon as you rev it up again it shoots the ltft to the mid to high teens.

bluehawk2

iTrader: (74)

Just a little Background on the car, incase it matters somehow

2002 SS 30k miles........Fast intake and TB LT's with the emissions hooked up.

TSP True duals O2 extensions and factory o2's Slp Lid and a freshly cleaned MAF



thanks!

bluehawk2

iTrader: (74)

here is a hp tuners log of this problem

bluehawk2

iTrader: (74)

here is another log on the dyno at vehicle load 1-4th gear bank on ltft stays reasonable, but bank 2 is still significantly unbalanced compaired to bank 1

BLK02WS6

iTrader: (2)

Definitely an exhaust leak... I would suspect the AIR tube and would block them off. If not that, then there is another leak somewhere... a lot of cheap headers leak in between the collector tubes and can be hard to find the leak.

bluehawk2

iTrader: (74)

yeah that is excactly what I had been looking for for a long time. I got the mirrors and the scope out, but there isn't a leak. The only one I found was at the collector and that was one of the first things I fixed.


I blocked off the AIR on both sides. It is still doing it.



All 4 plugs on bank two look exactly alike..............rich


We made a hit on the dyno last night with it

180 degree coolant 77 IAT The car made 341 rwhp with three degrees of knock at the beginning of the run.........weird thing is that it sputtered a little at the beginning of the run(which Im assuming was the knock that it detected) and then it cleared out.
afr was close to high 12's at the beginning and then dropped to high 11's by the end of the pull

The really strange thing is that we cruised it for a little bit after the run and the ltft's on both sides are down in the 1-2% range now

It's like after the dyno pull the car completly changed.

We let it cool and made another run except it was 160 degree coolant temp.
the car actually lost a little bit of power, but we had zero knock and AFR stayed mid to low 12's the whole pull. The fuel trims on both banks are still even and around 2 %


something happened during that first run.........what happened??


We did put a noid light on injector plugs to check the injector plugs, but that was the only thing that happened.



Gotta be the injectors or the diaphram on the fuel rail.


This car is an 2002 with 27k miles, so it has been sitting for a while.

BLK02WS6

iTrader: (2)

Wiring to the O2 sensor on that bank... something is making it think its lean at times when it is obviously not, and then dumping more fuel making it really rich. That won't be injectors or supply, because you are getting an intermittent false lean signal to the O2 causing it to dump fuel... follow me?

bluehawk2

iTrader: (74)

That is the same track I was on.............I was looking hard for a wiring problem with the o2 on that side, but the o2 wires are in the factory location un touched and connector didn't seem to have anything wrong with it as far as corrosion or a loose plug.

The car is acting perfectly normal now.............the o2's are switching really well and fuel trims at cruise and idle are under 3% at all times. Made another 340 rwhp pull on a stingy mustang dyno with no knock. After the pull we cruised it again and everything is back to normal. I just don't know what changed

Eagle02

iTrader: (20)

Sounds like electrical gremlins at work.

bluehawk2

iTrader: (74)

You are correct...................My friend drove it around this evening and everything was perfect until.....................lol PO300 mult misfire

What do you think is the starting point for that is? Grounds, cam or crank sensor?

could this still be a prob with the wiring to the o2 sensor


I havn't logged the car since this new po300 code poped up



thanks everyone
thanks everyone

crainholio

iTrader: (2)

Possibly your PCM was running in Open Loop mode if you just started it and went straight to WOT before it transitioned to Closed Loop.

This would mean one or more sensor(s) is sending bad data to the PCM. MAF, O2s are the usual culprits.

BLK02WS6

iTrader: (2)

I still say O2 sensor wiring based on the data you have provided. You switched the O2 sensors and it stayed on that side, so that rules out the sensor. The only thing that can cause a false lean on a bank is exhaust leaks or faulty sensor/wiring... Electrical issues that are intermittent can be very hard to find. These cars are getting some age on them, and the connectors and wiring can start to have problems. I would bet if you get someone to shake/move the wiring around on that side while you are logging it, it will probably show up.

I had a customer with a MAF problem that kept showing up... we put a new MAF on it, and the signal still went bezerk now and then... put a new harness on it... still did it. Replaced the PCM just for the heck of it, and almost a year later, it still runs great... gremlins!

bluehawk2

iTrader: (74)

Thats a good idea. It's really obvious when it was maxing out the ltft on bank 2.

I just don't understand the po300 code if it was a problem with the o2 wiring. It seems like it would have some kind of ho2 code, but we will go over all of that.



thanks

93BlackBeast

iTrader: (31)

Any updates to this issue? I'm running into an intermittent Lean Bank 2 as well where idle trims are identical to Bank 1 (-1.3) but as soon as the pedal is touched it skyrockets to around +20 or so.

I thought the same thing...exhaust leak, but like you, I've yet to find any that fix the issue.

Hopefully we'll discover something in the near future.

93BlackBeast

iTrader: (31)

Scratch that....I just read your post over on HP tuners and saw Frost's comment about the Misfire issue. Went and used his config(yes its 1am and I live in a neighborhood), but it didn't show up any misfires...but this time, my LTFT's were dead nuts on. My truck ran freakin awesome and I can't explain why I'd have an intermittent misfire, but I'm going to dig into it further tomorrow.

Anywho, thanks for the leads on hopefully nailing down my issue.

Cody B.