STUBBORN P0172 and P0101

Good day, 

I do appreciate coming across the forum as i have learnt from other people car related challenges. 

I am kinda DIY guy. I am being faced with P0172 P0101 toyota camry 2008 2.4ltr, 140K Miles... i have tried all i could to get rid of these codes even with the help of some local technician, but to no good result. The fuel trim is STFT -2.6% LTFT -35% I notice the LTFT does not fluctuate at all even on diffrent RPMS and on the high way. 

I have change MAF sensor, AFR sensor, Checked the PCV valve, checked for Vacuum leak, Checked/clean the injectors. I also notice the the car stall while trying to start on cool engine even worse on cold engine. It does this every morning on when the engine is cool. There is black smoke on the exhuast tail pipe and misfire somtimes at a stop light.

Please kindly advice as i have exhausted all ideas...

Check for an exhaust restriction, a plugged catalytic convertor.

I have checked both catalysts and confirm ok.

With the engine at hot idle and the trims skewed, no loads, what does the MAF g/s show? 

Maf shows 2.9 at idle 3.0 - 3.1g/s on load

Check power and ground and signal of MAF. Most likely your ground is bad. KOEO back probe harness side of MAF connector. Signal wire should read 5v. Power 12v and ground less than 100mv.

Thanks for response

If it’s the MAF sensor, how to I fix the power and ground signal on MAF Please ? Do I need to replace the MAF sensor or?
Kindly advice

You have a P0101 code which means your voltage is out of range on the MAF signal. It's not the MAF sensor but an electrical issue as you changed the MAF and still have the problem.

You need a volt meter and at least a basic understanding of electrical functions, testing, wiring and how sensors work. You can test wiring integrity (power,ground and reference signal voltage) with a volt meter but you have to have a oscilloscope to see if the MAF sensor it's self is working.

Because you asked how, this may be beyond your capabilities. Ask your mechanic to check the MAF wiring integrity. He should have done this. He may not know how. This explains to me why you're still having this problem.

Do not drive this car too much with this problem. Dumping that much fuel into the exhaust will burn out your catalytic converters.

I’ll have it looked on 

Thanks 

Signal is 5.3V but other wires reads  0.01 while the middle black wire which is earth reads 0.06 

paper clip could not go through the connector due to the tightness. 

see photos 

You have a five wire sensor harness. 3 wires are for the MAF and 2 wires for the IAT.
3 wires of MAF. 12v feed, 5v signal reference and a ground.
2 wires if IAT. 12v feed and ground.
I do not have wiring diagram for your Toyota but two outside pink wires should be IAT.
DO NOT use paper clip to probe female ends of a connector as this will bend the legs open and cause a bad connection. If you probe the female ends just touch them lightly.
If you do not have 12v on the feed wire for the MAF you have an open. You should have two 12v wires. One for MAF and one for the IAT. If no 12v, go to the ecm and check feed there. You'll need wiring diagram for this. If 12v at ecm then the MAF feed wire is open some where.

i.imgur.com/wNByFpL.png

You'll need to have the circuit loaded, meaning plugged in and key on, and take live measurements back probed while there's current flow. Since we're dealing with negative trims, my first thought is over reporting sensor and higher voltage which would lead me focus on the ground wire. A bad ground would elevate signal voltage I think, so check that one. I know the colors don't match but the designation for each pin should be right.

Hey im new to the fourm but a long time Scanner danner fan. Not sure if you have given this a shot but have you have taken a good look at your ECT? Have you taken it out and check it's resistance in both cold and hot conditions? This was one of my fault codes, but before i actually got the code i had noticed a less than accurate reading on the resistance, when the code finally showed up i just changed the thing.