2006 Camry P0171…

[Retired Army]

Had an 06 Matrix bought new. Nothing but brakes, oil and tires until the transmission went out with 310,000 miles. Loved that little car! Good luck with your Camry.

 

[jcountry]

+1 with above post...

Your MAS of 3.8 lbs per min (28.7 grams/sec) is three times normal for an idling car. Is your MAS reading 0.0 when engine off key on ? What is your MAP reading (vacuum), w/engine off key on it s/b 100 (atmospheric pressure of 30) and w/engine at idle somewhere in the 30-50 (about 15 lb vac) range and drop as throttle is applied. Running readings are engine dependent for each engine so I can't talk exact numbers for your setup.

What was status of car when you took these readings. Can you provide RPM and upstream O2 (pre CAT) B1O1 reading, it s/b swinging between 150mv and 770mv. The down stream O2 (after CAT) reading B1O2 s/b a steady voltage of about 1 volt and it is not used for fueling so it should not have anything to do w/trims being way off, normally signals bad cat or sensor for the emissions verification check only..

Your engine temp is at 190, was the car just started up, is that your normal temp it seems cool. The O2 (pre CAT) is used for fueling after car is hot, prior to that PCM is running in open loop using the LT trims stored in PCM from previous runs (that's the main use of LT trims) they are not used after engine is hot (closed loop/ O2 ready). Does you scanner display CAT temp it s/b above 600 degrees for correct pre and after CAT O2 readings.

Cleaned MAF sensor again.

Still doing the same stuff.

Long term fuel trim goes from &12% at idle to 30-40% under even a light load.

The second shot is after a drive. Warm engine. Engine off. MAF started at .3 on shutdown and dropped to .1 after maybe ten seconds

 

[canut]

The MAS now looks good on the last two graphs, MAS is within range .8 lbs./min and 1.0 lbs./min on each pic not the 3.8 in post #1. O2S1 is perfect 150-780 mv on each trace .

What I now see is two things:
1- Your ST Trims are -21.1 to -14.8 and -18.0 to -14.8 on the two graphs. That says the PCM is pulling 21.1-14.8 percent fuel to keep the O2S1 (emissions required) readings between a good burn of 150-780 MV. Usually ST trims more negative than - 24% will throw a rich DTC. However you are throwing a lean ( P0171 bank 1 DTC) that indicates PCM is adding fuel (+24%).

2- Does your car have two O2 sensors before the CAT ? Graph pic says O2S2 N/A. What I was looking for is a steady, non pulsing after CAT sensor reading in the 1 to 5 volt range (that says CAT is working) not sure what your scanner calls that sensor.

At this point I getting confused as the graphs now point to a rich problem. Not sure what to say here. Does not look like I am helping you to much...

 

[jcountry]

This is all the O2 sensor data I can get. First is idle and others are during short drive…. (I really appreciate your ideas! This has me flummoxed!)