Help!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Ryatt-Motion]

As some of you know about my troubles I have had with my daily driver, and for those of you who do not, I have a 2000 Camaro SS with an M6 with 96,500 miles. I bought the car early last year from the second owner and the car had 80,000 at that time. Almost a week after owning the car, I stomped on the throttle and kicked on the SES light; the codes were P0137 and P0157, which corresponds to the back o2 sensors in bank one and two respectively.

I replaced the sensors and drove the car for a while and noticed that mileage was total crap, and as fate would have it, the dern SES light came back on again with codes P0137 and P0157. I changed the sensors yet again, and noticed that my cat converters were bad as well, so I swapped them out for a set of 49 state legal Magnaflow factory install units that look nearly identical to the factory ones, but are not California Compliant. I also changed the sensors yet again. I bought a hypertech PP3 from a friend and installed the programming, and like a total dumb ass, put 100 octane in the car, not knowing it was leaded gas. I ended up getting the code again, and realized that I detroyed the o2 sensors by running the leaded gas in it.

Well, I decided to take the car to my exhaust guy and have him put in my SLP Y-pipe, and install yet 4 new AC Delco o2 sensors. I noticed the car seemed very nimble after all this, so I went home and installed a 160 thermostat and re-installed the Hypertech. The car seemed fine, but when I stomped on the throttle this morning on the way to work, the car kicked on the SES light again the codes readning P0137 and P0157. I removed the hypertech programming on my lunch and am going to see what that does. I also cleared the DTC's with the programmer as well, but I fear my problem is something far worse.

Here are the specifics on the car, it is bone stock, but has the dual dual performance cat back from SLP, along with a Blackwing airlid and Holly Powershot air filter. I have changed the plugs with AC delco' and replaced the wires with a set of GM Perfromance Parts 8mm wires. Everything else is bone stock. I notice that the engine runs noticably rougher than my other car (2002 LS-1), and it seems to hesitate once in a while, when taking off. Any help is greatly appreciated.

Rick

[Tony]

Almost sounds to me that a good tune is in order. If you have new cats, and new sensors, then you shouldn't get this code. But, and I don't know where you live, you could get them deleted out of the computer. But, I know that there has to be something wrong somewhere. Have you had a chance to hook it up and data log it to see what the sensors are saying? One thing that I would check is the injector pulse, it may be putting in a little too much fuel.

[Ryatt-Motion]

I hada a friend of mine hook the car up to his Tech II scanner that has all the new updates in it, and from what we saw, the car kept having intermittent misfiring in several cylinders, but he believed that was from the garbage ass plug wires I had before. So I replaced them with the GM wires and swapped the plugs and the code went away, but the mileage was terrible in the car. The one thing I notice is that this car does not have the same sack as my 2002 SS or my girls 2002-SS, this car seems to lag a bit in 1st and 2nd gear, and then decides to start motivating on top end. If this car were carbureted, it almost feels as though at WOT, I am running on the primaries without the secondaries kicking in if that makes sense.

[Randy L]

Ryatt,

You said you ran 100 octane leaded gas AFTER the new cats were installed. I wonder if you threw the 2 codes because of that. A google search reveals that leaded gas is bad for cats, though it will degrade them over time.

[m6speed]

leaded gas probably messed up your cats like randy l said along with those previous o2 sensors. if you know someone with a logging program like HP Tuners have them log your car as you drive it to watch the o2, it's probably compensating for a bad cat causing your car to run rough like that.

[Ryatt-Motion]

I ran the 100 octane that one time, and that was it. When I had my friend hook the car to his tech II, it did not emit a code for bad cats, but I alas, I have no idea what else it could be. My brother believes it could be faulty injectors which may be causing the car to run rich, or a bad ground, but I cannot trace anything anywher to where the ground is bad.

[KPI]

This can be something as simple as the wires not being pushed completely on the plugs or in the coils, or it can be corroded pins on the ecm plug or a bad ground, or even a maf that has oil on the wires and needs to be cleaned. It can also be a vacuum leak. Injectors? Possibly, but not likely. Checked/replaced the fuel filter?

[Ryatt-Motion]

KPI, I replaced the fuel filter last year at 87,000 miles I believe, the car now has about 96,600. I have pushed the wires on the plugs and wires, and I clean the MAF everytime I change the oil (I use MAF cleaner and douse it pretty good). I have run seafoam in the tank, I have purged it through the intake, nothing seems to help. The only one thing I have not done is replace the PCV calve, which I keep forgetting, but that would not do it would it?

I have not taken the connector off the PCM, but I have checked the connections, and they were tight. A part of me is thinking that my problem may be with the PCM itself because of the potential short in the system.

[Mase]

Your gone too far. the rear o2 sensors I doubt are the problem. rear o2 sensors do not effect how the car is running execpt in worse case secnories. they are there only to monitor the cataylitic convertors. Since the rear o2 sensors are reading bad before the front that makes me think you have an issue with the front o2 sensors most likly slow to respond and they cant keep up with how the car is running and its probley flooding the car out and the rears are picking it up. First thing I would do is take a scanner and monitor the front o2 sensors and see how fast they respond when driving. I would also check the fuel trims to see how the car is running.

[Ryatt-Motion]

Mase, I have replaced all four sensors, and i am still getting the codes. When you say to monitor fuel trims, what exactly are you referring to.

[Mase]

Fuel trims will tell you if the car is running too rich or lean. If its -5 to +5 then your good. anything else is bad.

[pmr253]

Originally Posted by Ryatt-Motion

Mase, I have replaced all four sensors, and i am still getting the codes. When you say to monitor fuel trims, what exactly are you referring to.

The fuel trim is stored in a fuel lookup table, there are two basic adjustments that the computer makes, short term and long term fuel adjustments. If the motor continuously has to make short term adjustments it might throw one of the values into a L Trims table. You shouldn't be getting large values on these S trims like Mase said. The easiest way would be to find a good running car and compare it to yours.

[Ryatt-Motion]

Originally Posted by pmr253

The fuel trim is stored in a fuel lookup table, there are two basic adjustments that the computer makes, short term and long term fuel adjustments. If the motor continuously has to make short term adjustments it might throw one of the values into a L Trims table. You should be getting large values on these S trims like Mase said. The easiest way would be to find a good running car and compare it to yours.

Hmm, this might be easier said than done. I no longer know anyone with a tech II. The only one friend I had has moved away. Is there any software I can purchase that is not going to break the bank that can assist me in this?

[99RedDvl]

The only thing I can think of Rick is exactly what Tony mentioned.. HPTuners but they cost a pretty penny ($499)

[Ryatt-Motion]

Whick kind?