question for mikel.....and anyone else that has an opinion

[joen]

I have a 1999 SS Camero LS1 and a u7198 predator. When I bought the predator I sent you my stock tune after I added these bolt ons....SLP CAI, SLP LID, SLP LT headers, SLP Loudmouth exhaust with high flow CAT's, and AIR removed. You then sent me a custom tune wihich I installed and seemed to work okay. Since that time I replaced my intake with an LS6, removed the EGR and deleted the P codes for EGR. I also had a problem with one of the CATs rattling, when I inspected the CAT and found that the element was lose inside of one of them so what I did was bust out the elements in both CATs and then put the hollowed out CAT back on in order to bridge the gap between the headers and the Y pipe...I did this in place of having a piece of pipe made to bridge this gap from the headers to the Y pipe.

So that is the history, now for the problem.

Since I did the LS6 intake, busted out the CATs and removed the EGR...I have seen that the bank 2 LT fule trims constanly run -5 to -7 less then the bank 1 LT fule trims, also at WOT the bank 1 O2 reads ~.91 mv while the bank 2 O2 reads ~ .97 mv. I replaced the bank 2 O2 already, and even replaced the battery as someone said that a bad battery could cause the sensors to read off. Still the problem, I have ried to adjust the LT fule trims but when I get the bank 2 LT fule trims close to zero the bank 1 trims start to read +5 to + 7 higher....I also adjusted the PE to compensate at WOT but I seem to be chasing my tail on this. I tried reloading the custom tune and still the same results.

So 4 questions....i

1) Is this custom tune wrong for my bolt ons?
2) Should I put the stock tune back?
3) And if I put the stock tune back will I still be able to remove the codes for the AIR and EGR?
4) Do you have a better custom tune to give me for the bolton I have?

Sorry for the long read on this but this problem has been driving me crazy.

JoeN

[06MonteSS]

with only one side being that far off, and you said you already replace the O2, I'd check for a leak somewhere in the piping. since you say you had taken it apart to bust out the CAT, could, could very well be a leak somewhere now, or even a hole in the CAT itself now.

the banks usually won't be the same anyway, but they shouldn't be THAT far off from each other.

[joen]

with only one side being that far off, and you said you already replace the O2, I'd check for a leak somewhere in the piping. since you say you had taken it apart to bust out the CAT, could, could very well be a leak somewhere now, or even a hole in the CAT itself now.

the banks usually won't be the same anyway, but they shouldn't be THAT far off from each other.

hmmmmm....very good point Monte....I will check that ASAP

[06MonteSS]

here's info about checking for exhaust leaks I posted the other day for another guy...

=======================================

Depending on the size of leak, it may sound like a hiss or up to a loud rumble.

Put your open hand near BUT NOT TO NEAR, the places your clamps are. If you feel air or pulsing, you have a leak. Also, make sure you don't over tighten your clamps. That will deform the tubing and cause leaks.

cover the tailpipe to force the exhaust through any leaks. Feel for leaks by running your hand near the exhaust system, without touching it. You don't want to burn yourself on these extremely hot parts.

Inspect the exhaust pipe where it bends over the rear axle, as this is a common area for cracks and leaks. Leaks tend to occur more often on pipes that are bent or exposed.

Start your hunt at the engine and follow the exhaust system all the way to the end of the tail pipe. Thoroughly check all connectors along the way, as these areas commonly have leaks.

Check the gaskets. This tends to be the most common cause of leaks.

Touch rusty areas on pipes and mufflers to see whether the rust is surface or goes all the way through the part. Areas weakened by rust often cause leaks.

[joen]

monte.....good tips on checkout...however, shouldn't only leaks prior to the numbe1 O2's be of concern? I have the rear O2's P codes deleted.....or is a leak past the number 1 O2 still going to be a problem??

[06MonteSS]

did you check starting from the motor? make sure all exhaust manifold/header bolts are tight... no intake manifold leaks anywhere since you put that new ls6 one on, right? no vacuum hose leaks anywhere??

[06MonteSS]

Any leak before or around the O2 sensor could cause outside air to be
drawn into the exhaust stream. The flow of exhaust gasses comes in the
form of pulses. The pulse itself will create a positive pressure, but after
the pulse, the exhaust system might contain a low pressure, which can
draw air through an exhaust leak. This air can trick the O2 sensor into
thinking the combustion was lean.

So even if the leak is after the O2 sensor, it could still cause an issue... depending on how close it was tho I would think.

[joen]

all very good info monte....i am off to check all you have suggested....i will let you know the results of ny findings.

[06MonteSS]

cool man...