My car threw a couple codes. The one that concerns me is 44, Left Bank Lean. I read the sensors and here is what I got.

start up
IAC: 24
Spark Advance: 18
02 L: .15 or lower
02 R: .15 or lower
BLM Cell# 16
BLM contents: 128
Integrator L: 128
Integrator R: 128

Warm (closed loop)
IAC: 28 (30 when fans on)
Spark Advance: 20-21
02 L: .15 - .6
02 R: .15 - .75
BLM Cell# 16
BLM contents 130-131
Integrator L: 131
Integrator R: 127


These are at idle, under throttle it obviously changed. The 02 readings were .1 - .9 on both under throttle. What I'm concerned about is the integrator readings, they were always at 128 before, even when running hot. Also, the 02's are reading very low, mostly around .075, when it first starts up. Same with the BLM contents, it was almost always at 128, but changed to 131 to 133 depending on idle. There is also a loud ticking noise like a broken flexplate, but I got under there to check it and did not find anything wrong. The noise comes and goes.

Is it time for new 02's (191k miles)? or is there something else causing this change? Is it normal for a low 02 reading when it is just started up, but not always cold?

 

it's probably not an issue at idle, i don't see it. what's the fuel pressure? does it fall off under load?
noises can be a real pita, over the internet they can be impossible. more info on exact conditions to get it to make noise can give you a better chance of someone guessing right.

 

The fuel pressure is fine. It sits at 39-40 at idle, and jumps to 50ish at WOT. Here are a couple runs at about 3/4 throttle.

1st 3/4 throttle
02 R: .1-.9
02 L: .1-.9
BLM Cell# 15
BLM Contents: 125
int R: 122-133
int L: 122-133

2nd 3/4 throttle
02 R: .1-.9
02 L: .1-.9
BLM Cell# 17
BLM Contents: 123
int R: 118-128
int L: 113-127

3rd
02 R: .1-.9
02 L: .1-.9
BLM Cell# 2
BLM Contents: 128
int R: 128
int L: 128

On the third run the integrators held steady at 128, and the 02 readings changed even and consistantly. On all three runs the 02's jumped around .4-.9 mostly, but did jump to .1 sometimes.

As for the noise, I understand it's near impossible to locate/diagnose it over the internet. If it helps, it does it mostly when just warming up, and only at idle. It's also only audible inside the car, standing outside the car there is too much noise to pin point it. I already checked for a cracked flexplate, that's not it, and converter bolts are tight. I will check for exhaust leaks.

 

The code sets when the PCM sees an O2 signal of 200mV or less for 50 seconds. Could be a wiring problem, could be a sensor problem. I don't see any evdience of this actually happening in any of the data you posted. Its really not of much use to try and provide static readings of a system thats moving as fast at it does. A scan log is more useful.

Why are you concerned about low O2 readings when the engine first starts? Is your AIR system still operating? A cold start with cold sensors will typically show ~450mV, since that's the voltage the PCM supplies to the sensors, and the sensors can not generate any voltage of their own when they are cold. As the sensors warm up, if your AIR system is operating, its normal for the readings to drop at low as 003mV's just before it kicks into closed loop.

A BLM change from 128 to 131 represents no more than a 2.3% change in the fuel calculation. If they were rock steady at 128 before, that may be the first signs of an exhaust leak, misfires, low fuel pressure, faulty sensors, etc. But 131 is not a "bad" number.

The INT's should not be 128. They should swing rapidly on either side of 128 in closed loop. That's how the PCM swings the A/F ratio from slightly rich to slightly lean, back and forth, to provide the cats with the reserve O2 to complete the oxidation reaction. The AVERAGE of the INT's should be 128 over a long period of time. If the average is above or below 128 for an extended period of time, the PCM will then move the BLM's up or down to drive the AVERAGE INT's back to 128. That is the "learning" that the PCM does.

Your "2nd 3/4 throttle" data is suspect. Cell 17 is the decelleration cell.

"Ticks" are often exhaust leaks.

If you have almost 200K miles on the original O2 sensors, it would be a good idea to replace them.