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Discussion Starter · #1 ·
hey guys 96 ss bank 2 running very lean changed o2 injectors fuel pressure regulator and coolant temp checked for vaccum leaks and there is none also replaced egr and there is no exhaust leaks . any idea's as to what is going on thanks
 

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thanks for your reply quick question i had a noid light on it very bright and it runs good cold this is really strange. could there be such a thing as an internal vacum leak like a problem with head
 

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Question: How did you figure out bank two is running lean? red hot manifold, computer readout...?

Check for an exhaust leak on bank one.

Also check the rubber elbow going into the passenger side of the throttle body - sometimes this cracks and lets air in.

Also check the lines running from the evap canister.

Look for burnt wires, especially coming from the O2 sensors.
 

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When you put the noid light on, leave it on and wiggle the injector connector wires, main harness, shake it ect... It could easily be a break that isn't noticed when a noid light is just sitting in there, but when the car is moving and the wires are vibrating you are losing connection.

Check voltage on each each injector harness. Make sure you are getting the same voltage to all.

Ohm out each injector, make sure one isn't a much lower or higher resistance than others. They should all be fairly close.

Even if all this is good, it doesn't rule out a mechanical problem with an injector such as a clog or problem with the pintle...

A cylinder misfiring could be mistaken for a bank running lean. An igniton miss will cause a fresh shot of oxygen to be pumped out past the 02's causing them to read a low mV on a scanner. You have quite a few things to check. Plugs, wires, corroded points or carbon tracking on the distributor ect...

I second stone's question on how do you figure the bank is lean. Are plugs white? What do the BLM's/Long term fuel trims say on your scanner?
 

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Discussion Starter · #6 ·
my long terms bank 1 0-3 bank 2 is max 25 %. the right side headre glows after it been run. i am wondering possible 02 sensor harness problem. key on engine off bank 2 02 reads 25% long term. any way to trick the computer with 02 sensor to make it run right. thank guys!!!!;)
 

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If no leaks I would swap O2's from side to side to see if it follows O2's..
 

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Clogged cat?
 

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Maxed out it's not an 02 sensor IMO...well at least I have never seen one do that. When you look at the scanner, what does the 02 sensor mV do on that side. Does it oscillate, just at a very low voltage, or does it not move at all? Just to rule out the 02, you could always just swap sides.
You really just need to systematically check everything...

Do you have cats?

Does the car run like it has a misfire?

I'd start with checking all the plugs and seeing if one is different than the others, this way you can narrow it down to one cylinder or a problem that is really affecting the whole bank. You don't know by looking a scanner, because one or two cylinders my be misfiring causing the 02's to believe the whole bank is lean.
 

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You say you have headers, there is a quick way to determine if its a single cylinder or the entire bank, beg, borrow, steal an infrared thermometer gun and take temperature readings on each primary pipe with the engine started "cold" in the morning. Let the engine fully warm up and recheck the primaries, there shouldn't be much more than 50 degree difference on the outside temperatures of each tube. If they are stable, the problem may be the cat overtemp subroutine is coming into play and dumping fuel into the pipe, making it act like it has too far retarded timing. recheck after a drive that would normally make them glow and recheck temps. expect temperatures in the 850-1000 to make the header glow.

As asked before, does the car have cats? do you have a balance pipe, what headers do you have and do you have a tune, if so did they correct the individual cylinder fuel trim tables to correct for the dynamic change in the exhaust tract at idle and off idle.
 
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