The Never Ending Lean Bank 2 Saga........

I am about ready to junk this thing.

I have been chasing a lean bank 2 issue for over a year. STFT and LTFT are maxed for bank 2, perfectly normal for bank 1. Upstream O2 sensor on bank 2 rarely goes over 0.050 V and the downstream rarely goes under 0.9V.

So something is telling the sensor that it is lean and it is dumping fuel in and has of course fouled the plugs and screwed the sensor.

I have replace the pcv system (not leaking), resealed the intake (BBK SSI) more than once, new plugs, wires, and coil packs, clean MAF, and put a few different new O2 sensors in.

AIR system has been removed and codes deleted.

No matter what, lean bank 2. Off the chart lean.

Only things I have not checked is exhaust manifold leak. Completely stock (and new cats) exhaust except for cat back.

I have no idea what to try next. Can something mechanical (lifter, spring, etc.) cause this problem?

Thanks for the help.

Jon

I've read countless times of people with that intake having lean issues on one side. Do you still have the stock intake to put on there to completely rule that intake out? It could be other things but with that intake I would want to completely rule it out before moving on to something else. Spray some carb cleaner around that passenger side of the intake and see if the idle increases but a much better solution would be to switch back to the stock intake until you find the culprit. How was your air system deleted? Did you cap the manifold where the valve sat? How did you seal that off? Have you swapped injectors side to side to see if the issue follows it to the drivers side to rule out an injector issue?

I wish I had an LS1/6 manifold to put on. Bought the car with the BBK on it. This time, I rtv's around the perimeter of all the intake O-rings thinking it would help. Got it started in the garage, as soon as it went closed loop, the upstream sensor on bank 2 went low and stayed there. Very disappointed. If I had the stock LS6 intake, it would have been on there already.

I did swap injectors side to side, made no difference.

I bought the aluminum block-off plates for the AIR delete, used a factory gasket under it with rtv on both sides.

Ideas?

Jon

I agree with 0rion. For all you know, that BBK intake could possibly be warped. Search ebay for a good used LS6 intake manifold and swap that on. Hell...you could take the LS6 manifold to a performance shop and have it ported.

Found an LS6 out of a 04 GTO with tb and fuel rails, seeing if I can make a deal.
Will all of this just bolt in place since the BBK was in there before?
Jon

before I just ran out and bought an ls6 intake I would want to know that the intake is in fact the problem. Have you checked local boards to see if someone had even an ls1 intake you could borrow just to test with?

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Originally Posted by 0rion

before I just ran out and bought an ls6 intake I would want to know that the intake is in fact the problem. Have you checked local boards to see if someone had even an ls1 intake you could borrow just to test with?

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I understand what you are saying, but honestly, I hate this BBK setup anyway. I got the LS6 intake, tb, fuel rail and injectors delivered for $375. Even if this is not the problem, I'll be glad to be rid of the BBK setup.
Jon

Quote:

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Originally Posted by jfl330

I understand what you are saying, but honestly, I hate this BBK setup anyway. I got the LS6 intake, tb, fuel rail and injectors delivered for $375. Even if this is not the problem, I'll be glad to be rid of the BBK setup.
Jon

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Hopefully solves your problem. That's a good deal. I got my LS6 intake brand new a few years ago and I pay around $350 shipped.

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Originally Posted by JayTA98

Hopefully solves your problem. That's a good deal. I got my LS6 intake brand new a few years ago and I pay around $350 shipped.

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Me too, but even if not, I'll have one more variable taken care of. If this does not resolve it, then it is either an exhaust leak or mechanical(pushrod, spring lifter, etc.).

Having pulled that BBK a few times now, I will be glad to have the original LS6 on there for a lot of reasons.

Jon

The LS6 intake is a direct bolt on. Has the EGR/AIR system already been bypassed/tuned out?

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Originally Posted by cammed goat

The LS6 intake is a direct bolt on. Has the EGR/AIR system already been bypassed/tuned out?

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It's an 02' so no egr, and the air has been deleted and tuned out. Very excited about this!

Then nothin to it but to do it. Bolt it in and keep us posted.

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Originally Posted by cammed goat

Then nothin to it but to do it. Bolt it in and keep us posted.

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Count on it!

Ridgewood still have that great July 4th fireworks show? Lived in Saddle Brook/Elmwood Park/Englewood/Fort Lee for 20 years.

Yes they do. :D

What O2 sensors did you use?

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Originally Posted by SMWS6TA

What O2 sensors did you use?

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I've used delco, Denso, and others, always same result for b2s1.

OP take with 88gtman. He has a BBK intake and might be able to help you out. He's had is for a long time now and as far as I know of no issues.

My BBK has been great. 3 years and 20k miles so far without a problem. Have you checked the injectors? Or sprayed carb cleaner around the engine bay to search for vacuum leaks? A clogged injector on that side could cause the problem.

Quote:

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Originally Posted by 88gtman

My BBK has been great. 3 years and 20k miles so far without a problem. Have you checked the injectors? Or sprayed carb cleaner around the engine bay to search for vacuum leaks? A clogged injector on that side could cause the problem.

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in post 3 he said he swapped them side to side and no difference. Exhaust leak on that side is about the only other thing other than the intake that I can think of that would cause the problem. If it were a valvetrain issue I would think he'd be able to hear that. Checking the exhaust over there wouldn't be a bad idea but many people have had issues getting that intake to seal correctly so it still has to be on the table as a cause until it gets ruled out.

LS6 intake going in tomorrow along with new exhaust manifold and pipe gasket. Found 4 good NGK's and an O2 sensor for that side since I am sure what's in there is completely fouled. Intake came with 80K mile injectors/fuel rail out of an 04 GTO and I am throwing them in too. Hope by tomorrow afternoon this will be the end of this issue.

I will post O2 sensor data, stft's and ltft's after I run it.