32 = EGR failure:
A egr failure will set this code. Either a faulty egr valve, egr temp. switch or the egr control solenoid. . When the egr solenoid is operating properly, the ecm will activate it, allowing vacuum to open the egr valve, this in turn will allow the hot exhaust gases to circulate through the egr valve, and the egr temp. switch will heat up until it reaches its activation temperature, will close and send s grounded signal back to the ecm telling it the conditions have been met. If the switch is closed on start up or does not close when the operating parameters are met, this code will be set.
44 = Lean Exhaust Condition:
This code will be set whenever the ecm perceives a lean exhaust condition. The main causes for this is a grounded O2 sensor, low fuel pressure, restricted injectors, contaminated fuel, exhaust leaks or bad air switching valve. The condition met to set the code is a low O2output voltage (less than 0.2V)around a minute with the ecm is closed loop.
This is from a TPI site, so the EGR does not operate the same way, but I am pretty sure that the codes mean the same thing between the two.
With my TBI truck, I had to actually remove the intake, and shoot my sandblaster down the EGR bore to clean the carbon out. It didn't work prior to that, and it looked ok too. If you go that route, be 100% sure that you get ALL the sand and dust out of the intake before you consider bolting it back on, and make sure that the EGR is cleaned up. Also, replace the solenoid, it may be faulty as well -- You can find it on the passenger's side of the engine, by the spark module.
Your lean condition is probally caused by the headers. They do one of two things -- First is help the engine breath better, which means that it needs more fuel, and second, by the time the exhaust gases get to the 02 sensor, they are usually too cool for the 02 sensor to work correctly.
Also it could be just the 02 sensor getting old. With age, they stop working as well, and eventually produce so little voltage that the ECM percieves a lean condition, and pours more fuel than is needed into the engine (would explain why your 02 sensor is black, it should be a nice golden brown color) Don't get any typical parts house 02 sensor when you replace it. Get an AC-Delco heated 02 sensor. They are the best you can get, and have an internal heater so they get into closed loop faster (or in the case of headers, at all)
Just gotta hook the two coil wires up to ground, and an keyed ignition source, and the third wire to the stock 02 sensor wire to the ECM.
