Codes for AF sensor and APP sensor
 

I took my car to Auto Zone to have the codes read. Yes Auto Zone. First I am tight with my $ and 2nd there are not too many Acura Dealers close by in Iowa.

I thought it might be my APP sensor going bad after reading all the posts. This is what they came up with:

P2197
P2195
P2138

Lean AF ratio-Vacuum Leak- low fuel pressure
Check other codes first
Failed AF sensor

App Senor

I am pretty sure I will replace the APP sensor but what is the AF sensor and is it easy to replace? Any help is appreciated.
Thanks

Couldn't get the link to work off of ISIS, sorry. So here's the copy and pasted version.

Service Bulletin
 2004 American Honda Motor Co., Inc. – All Rights Reserved BTB 27088-27438 (0407) 1 of 2
CUSTOMER INFORMATION: The information in this bulletin is intended for use only by skilled technicians who have the proper tools, equipment,
and training to correctly and safely maintain your vehicle. These procedures should not be attempted by “do-it-yourselfers,” and you should not assume
this bulletin applies to your vehicle, or that your vehicle has the condition described. To determine whether this information applies, contact an
authorized Acura automobile dealer.
July 23, 2004
04-016
Applies To: 2004 TL – ALL
MIL Comes On With DTC P2195 or P2197
(Supersedes 04-016, dated May 21, 2004)
SYMPTOM
The MIL is on, and DTC P2195 (rear air fuel ratio
sensor signal stuck lean) or P2197 (front air fuel ratio
sensor signal stuck lean) is set.
PROBABLE CAUSE
The ECM/PCM software incorrectly interprets sensor
inputs, causing the codes to set.
CORRECTIVE ACTION
Using the HDS, update the ECM/PCM.
WARRANTY CLAIM INFORMATION
In warranty: The normal warranty applies.
Failed Part: P/N 37820-RDA-A04
Defect Code: 07201
Symptom Code: 03203
Skill Level: Repair Technician
Out of warranty: Any repair performed after warranty
expiration may be eligible for goodwill consideration by
the District Parts and Service Manager or your Zone
Office. You must request consideration, and get a
decision, before starting work.
REPAIR PROCEDURE
NOTE:
• Before you update an ECM/PCM, make sure the
battery in the vehicle is fully charged.
• To prevent ECM/PCM damage, do not operate
anything electrical (audio system, brakes, A/C,
power windows, moonroof, etc.) during the update.
1. Use the HDS to read and clear the DTCs.
2. Use the HDS to update the ECM/PCM:
• If not already done, load software update
1.012.023 or later onto the HDS.
• In the HDS main screen, click on the
reprogramming icon.
• In the System Selection menu, select PGM-FI,
and click on the confirmation check mark.
• In the screen that shows the new program, click
on the confirmation check mark.
• In the Confirm the Control Module Update
screen, click Yes.
• When the programming is complete, click on the
confirmation check mark.
NOTE: Do not disconnect the HDS, and do not
turn off the ignition switch.
• In the Updating Honda Control Modules with
HDS Tablet screen, click on the confirmation
check mark.
• Wait until the programming is complete. This
programming takes about 10 minutes.
OP# Description FRT Template ID
123503 Retrieve the DTC(s), and
clear the codes with the HDS
0.3 04-016A
125517 Update the ECM/PCM
software with the HDS
0.3
122505 Do CKP pattern learn 0.3
REPROGRAMMING ICON
2 of 2 04-016
3. Do the ECM/PCM idle learn procedure:
• Make sure all electrical items (A/C, audio, rear
window defogger, lights, etc.) are off.
• With the HDS, do the ECM/PCM RESET and
CKP PATTERN CLEAR.
• Turn the ignition switch to the ON (II) position for
30 seconds.
• Start the engine, and let it warm up to its
operating temperature (the cooling fans cycle
twice).
• Let the engine idle (throttle closed and all
electrical items off) for 10 minutes.
4. Do the low-rpm CKP pattern learn:
• Test-drive the vehicle on a level road: With the
A/T in the Sequential Sportshift mode and in
second gear, or the M/T in second or third gear,
decelerate (with the throttle fully closed) from an
engine speed of 2,500 rpm down to 1,000 rpm.
• Stop the vehicle, and put the transmission into
Park or Neutral. Set the parking brake. Do not
turn off the ignition.
5. Connect the HDS to the DLC, and check the status
of PULSER F/B LEARN:
• On the Selection Menu, select PGM-FI.
• On the Mode Menu, select Data List.
• Check the value of PULSER F/B LEARN.
• If the value is Completed, go to step 6.
• If the value is Not Completed, be sure the
engine is at normal operating temperature (the
ECT SENSOR (1) value is 176 or higher), and
repeat step 4.
6. Do the high-rpm CKP pattern learn:
NOTE: The low-rpm CKP pattern learn must be
completed before you do the high-rpm CKP pattern
learn.
• Test-drive the vehicle on a level road: With the
A/T in low gear, or the M/T in first gear,
decelerate (with the throttle fully closed) from an
engine speed of 5,000 rpm down to 3,000 rpm.
• Stop the vehicle, and put the transmission into
Park or Neutral. Set the parking brake. Do not
turn off the ignition.
7. Connect the HDS to the DLC (if not already
connected), and do this:
• On the Selection Menu, select PGM-FI.
• On the Mode Menu, select Data List.
8. Check the value of PULSER F/B LEARN (HIGH
RPM):
• If the value is Completed, you are finished.
Disconnect the HDS.
• If the value is Not Completed, be sure the
engine is at normal operating temperature (the
ECT SENSOR (1) value is 176 or higher), and
repeat steps 4 thru 7.

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As for the APP sensor code, as your research shows, it's usually safe to say it's the sensor itself. Easy to replace, I've done quite a few at work.

Good luck!

-- Kevin