1. I am getting "Permenant DTC Code C0A00 and C0A01 - what are these codes?
2. I am getting DTC Code C0700. Several weeks ago I got C0701. I recently replaced 1 tire on my Buick Enclave AWD. Could this be related.
3. How do I diagnose this problem to determine what the issue is?
Depending on the scanner you're using, the weird codes with A in them sometimes mean that the scanner can't interpret it properly and you might need a better scanner, like a Tech 2. C codes are for chassis. I'm not finding anything except for C0700 "Level control accessory inflator switch circuit high" and C0701 "Level control accessory inflator switch circuit open". Does it have rear air bags for the suspension? Looks to be an issue with that system.
Thanks for the reply. Turns out my software I was using was giving me incorrect codes. The actual code is P0420 - Cat Converter Below Efficiency Bank 1. I hooked up my software and went for a test drive and these are the results I got:
1) Fuel Pressure is within specs for Buick Enclave 2011
2) O201 sensors fluctuate normally on Bank 1 and 2. O202 sensors on both banks tend to stay between 0.665-0725 but have gone up to around 0.835 or down to 0.1 on acceleration/deceleration. It did seem that both rear 02 sensors acted pretty evenly but maybe Bank 1 sensor fluctuated just slightly a bit more... it was not quite evident.
3) During a Lean test (removed the intake from the air filter momentarily) the rear 02 sensors reacted immediately by dropping to 0.1. During a Rich test (sprayed Brake Fluid into the intake) the rear 02 sensors reacted at first by jumping up high then they stopped reacting quite as fast the more I sprayed.
4) There is no smoke noticeable from the exhaust during idle or quick acceleration.
5) The Long Term Fuel Trim for Bank 1 is showing as +9.4% and Bank 2 +7.0%. Is this a rich condition or normal one?
6) I recently (about less than a month ago) removed the Intake manifold and replaced all the plugs. Plugs appeared to have normal burn. One plug in Bank 1 did appear to have a small bit more gunk built up on it than the others but still had normal burn color.
Any idea on what this indicates or other tests I should do?
Although +/-10% is considered "normal", you're awfully close to it. I consider anything +/-5% to be abnormal. With your + values, it's adding more fuel to compensate for a lean condition. You might have a vacuum leak somewhere. You should try and find it using carb cleaner. Concentrate on the intake manifold since you have removed it for the plugs. (You have to remove it for the plugs? Geez!)