Unfortunately I'm having the same problem a lot of people are on here lately. The car's running incredibly rich, gas mileage horrible, and slight hesitation/surging at lower rpm's. I've replaced everything I can think of so far except for the O2 sensors. My current two O2 sensors are just over a year old - replaced March 2003 during a Mac header install. The other two rear ones have been programmed off by Madwolf. Here's a small list of what I've done so far....

replaced opti
replaced coil with MSD coil
replaced plugs
replaced wires
fixed intake manifold leak
replaced water pump (old one failed.)
replaced water pump temp sensor

Also,

I have no burnt wires and no exhaust leaks.

I have Autotap ( I'm currently at work ) and can't scan the car just yet until I get home.

So, would it be stupid to program off all your O2 sensors? I'm curious because I know these things are expensive to replace and people seem to keep having the same problems with these dying O2 sensors. I'm just really tired of the bad gas mileage and missing.

Just an example, I went out to dinner with my family a couple of nights ago. It was nice out so I decided to take the Z. Well, the restaurant was about 6-7 miles from my house, and it took me ALMOST a half a gas tank to get there and back with no WOT runs at all. (totally serious.) Something is seriously not right with my car.

Interesting point you bring up, can anyone at to this topic.

I wouldn't do it unless you are going to switch to a fuel injection system that is designed to run without them. The stock fuel injection system tends to run rich and depend on the O2 sensors to adjust it for different conditions and loads. You would at least have to rewrite the entire fuel map.

Have you checked the fuel pressure?

Sure, you *can* do that. What you would be doing is running an Open Loop program. You set a parameter (such as Min cool temp for closed loop) to a level that can not be reached (150.5°C for instance), and you will never enter closed loop and thereby not use your o2 sensors for feedback.

I've been running an open loop program for about 2 years now, it has its advantages and disadvantages. There is no searching of the o2 sensors and the subsequent corrections to the fuel delievery, so everything feels smoother to me. Gas Milage was not one of my concerns though and I still have a lot of tuning to to if I want it to run efficiently (just a toy for now).

I think this could be used to accurately tune the A/F but it would require, IMO, a lot of time and constant monitoring and adjusting, as well as a suitable sensor to tune with (wide band O2). I plan on having a semi permanant mount wide band O2 sensor within the next couple months (LM1, hopefully with a newer interface, to switch between my two cars for tuning) and then I'll get back into the PCM side of things on my T/A.

LM1 can be seen here...

http://www.innovatemotorsports.com/lm1.php

Don't know if that is the answer that you wanted, but that is my take on it anyway. You can't really just program out the front o2 sensors like you can the rears. The rears are really nothing more than a check that your catalytic converter is still in place and functioning. Programming them out is nothing more than just telling the PCM not to set the CEL for rear o2 failure.

HTH.

So, in other words, I should probably just replace them. Any other suggestions or advice to my problem?

It sounds to me like you may have a bad MAP sensor. Have you looked into this? The easiest way that I can think of to check this is by unplugging your MAF. Then your car will be MAP dependent and if you are having a problem with it, it will make it very apparent.

What do you mean by "apparent?" Will it run differently? I thought with unplugging the MAF, the car would die? Then I could restart it and see what happens??

If you unplug your MAF your car will not die. It just wont be taking a reading from your MAF and like he said , it would then have to rely on the MAP.

With the limited amount of mod's to the engine, there is no reason it shouldn't run fine with the front O2 sensors. Going to open-loop programming would possibly cover up the problem, more than cure it.

You need to make a few logs with AutoTap, and post them for people to review. If there is a problem of the magnitude that is causing it to use 6 or 7 gallons of fuel in 6 or 7 miles (are you serious?), the problems should be reasonably visible in a data log - he!!, there should be raw fuel pouring out the exhaust pipe like a garden hose. And the engine would be hydrolocked.

I run "open-loop", but I'm also making 800HP on higly leaded fuel, and have an unbelievable number of engine dyno and chassis dyno runs that were used to tune it.

I will run the car on Autotap this evening when I get home from work. But to answer your question, yes I am serious. And I also let the car idle in the garage for a few minutes when I got home that night and it left black carbon/fuel residue all over my garage floor. The idle was very choppy, and very hesitant during driving conditions. Almost sounded like I had a cam. ( I wish. )

But anyhow, I will post Autotap results this evening - thanks for all your help guys!

It really sounds like an O2 sensor problem. Did you use the GM sensors when you replaced them.....many people have trouble with the aftermarket O2s. Have you ran any leaded fuel or fuel addatives that may have contaminated the O2s.......some silicon based sealants can also contaminate the O2s.

Did you try the MAF thing. It is an easy test to eliminate your MAP sensor as a culprit. Unplug the MAF and drive your car for awhile. If it is worse than it is a MAP problem.

Did you get this figured out? My car goes through oxygen sensors like crazy. I am considering trying to just run an open loop tune. The car runs/idles so smoothly that way.

Of course my BLMs are split. No vacume or exhaust leaks.

Lol, this thread is more than 2 years old. The guy may not even still have the car.

Hey, at least he did a search, not like half the people on here that asked the same question that's been answered a million times.

I was also having this same problem and ended up being contaminated O2s from silicon.