2007 Toyota Camry consumes fuel and runs rough

My Toyota Camry 2007 XLE 4 cylinder consumes fuel and runs rough (it jerks sometimes when changing to gear to 2. It delays on acceleration) I hook up a scanner and found out some codes

See attachment

I have change the charcoal canister as the car was cutting off fuel flow from the nozzle when refueling, which has stopped.

I collected a working MAF sensor from a friends car drove it for days, the codes came back 4days later.

Changed air filter

Checked for vaccum leaks

I checked the fuel trims
LTFT is -30% STFT is 1.6%

Codes keeps coming back especially the p0172 & P0101

Kindly assist me please as I am tired. I have also taken the car to 3diffrent auto mechanic, still no solution.

Kindly work me through on how I can diagnose it myself as the auto mechanic we have here can’t seem to provide solution. I don’t have a big OBD2 scanner, I have the phone app own .

You have, already, replace a flooded canister. Is it possible that fuel remains in the EVAP lines? Disconnect the Purge Line from the intake, creating a vacuum leak. Do your Fuel Trims go positive? Plug the vacuum leak. Now, what do your trims do? Also, check to make sure that the EVAP Vent is working/flowing, properly.

Thank you for your response. Pardon the delayed reply

The gas cap is tight as I changed it not too long ago.

I disconnected the purge valve as advised then start the car, there is no flow. LTFT remains -29% though, it was -10% when I first started the vehicle as it starts warming up it jumps to -29%

Maf PID fluctuates between 3.89 - 4.18g/s

No long crank time as the car starts quick at once

No issues starting after refueling.

Thanks for the response

I did create a vacuum leak as there was no change LTFT remain -29% . same thing when i connected/ disconnected the line from the purge valve to the intake

Where is the EVAP vent located please ?

Maf PID fluctuates between 3.89 - 4.18g/s.
Should read around 2.5vg/s at idle suspect faulty MAF sensor causing ECM to subtract fuel.

I have tried like 4 different MAF it’s same reading… sometimes I get 2.9 g/s and sometimes 3.8

Have you resolved the problem?

Have not been able to resolve the problem. I noticed when the car is in park and idling, if I hit the gas pedal the LTFT reduces from 28% to 15% if continue pushing the gas pedal while still on park it it get to 8%. Same thing while driving on an Express way. It does not get below 8%

The car is just being annoying

I don't have long crack time or stalling after refueling. MAF at key on ignition reads 0.95 g/s . I have even tried a working MAF from a friend's car, it's came result.

I noticed also when disconnected the MAF and stars the car, it went on open loop as the LTFT drops to 10% while engine running.

have you checked your pcv valve to make sure it is functioning correctly

A few things would help me understand more... in my opinion, I think you have a MAF wiring problem. The symptoms you have happen with a problematic MAF. As you changed the MAF sensor, its not the sensor but you still have the P0101 which tells me the MAF signal is messed up.

The reading of 3.8 to 4.8 g/s was that with the engine running at idle? If you can, what is the MAF voltage at idle.

The MAF wiring on your XLE. To be on the same page, is it 5 wires. 1 Pink, 1 Green with a Red stripe, 1 Black with a White stripe, 1 Green and 1 Brown or Tan.

Do you know how to back probe a wire? I will be asking you to take voltage measurements with the MAF connector plugged in and unplugged.

When the engine is running on park, MAF sensor now 3.10 g/s

There are 5wires white, light red,yellow,purple and light green.

I can try to back probe it. But I don't think the multimeter pin would fit in at the connector when the MAF is connected

Checked PVC, it's working fine

How do i trace this maf wiring problem ?

Please help

Yes please

Yes, -28% to -15% down to -8% when I hit the gas pedal

The P0101 my be an affect not the cause of your rich problem. At this point I would be looking at my 02 voltage readings and if the heater circuit is working. The downstream 02 will give you an indication if the upstream is working properly. The heater circuit on the 02 my not be working and when you increase RPM hot exhaust gases heat the 02 and it works for a short time. Using your scantool try and graph the voltage of the upstream 02. Depending on its type, wide or narrowband, the pattern will differ. Narrowband will oscillate between 100mv and 900mv. On startup on cold engine, the voltage will start high and after a min it will drop low around 100mv then start oscillating. A wideband will not, it will be steady at around 3.3v after warmup. Wideband AF's heaters work at a much higher temp, so it's more critical that its working correctly. But, here's where it gets tricky. A wiring problem can cause an 02 to give false readings. You will have to use a multimeter and check the wiring circuit integrity.

If you're game, everyone here will give as much help as possible, but it might be easier to find a good shop to fix your problem. I hope this info will save you money, time and aggravation in solving your problem. Sincerely VegasJAK

Thank you so much for your response.

I scanned the car again and I got these codes

Though, instill have a high fuel trim. I also tried another O2 sensor as there is no change. LTFT is still high, car still emitting black smoke and runs rough