This is my first time using my own code reader to diagnose a check engine light.

P0108 seems to indicate a MAP sensor fault.
P0455/P0456 seem to indicate a leak in the fuel pressure, likely the fuel cap.
C1555 looks like a scanner incompatibility.

I am using Torque Lite and a BAFX OBD2 reader to get this data from my 2007 TL 3.2. Prior to the check engine light coming on, the dash screen was telling me that the fuel cap was loose, despite me re-tightening it a few times for a couple days. The engine struggled a bit on startup once this weekend, but I would attribute that more to the cold weather.

Which should I go after first, the MAP sensor, the fuel cap, or just replace both at the same time? Anything else I should know about these systems? This is not my first time replacing sensors, though it will be my first repair job on the TL.

 

P0455/P0456 - Could be caused by a faulty Purge Valve Solenoid. Do you get the tighten gas cap notification on the dash?

 

Yes. This happened a few days prior to the CEL.

 

Replace this part. This should clear up your P0455/P0456 CEL's

https://www.acuraoemparts.com/oem-pa...1hbnVhbA%3D%3D

 

P0108 is related to this part. Check to see if the wiring is good otherwise replace part.

https://www.acuraoemparts.com/oem-pa...1hbnVhbA%3D%3D

OR

refer to this good search to help find an answer.

https://www.google.com/search?source...j0.zFuDxFudzqE

 

C1555 - Unknown. Clear the other codes and take action to replace parts or inspect as mentioned. See if any codes come back.

 

Looking around the interwebs, it looks like cleaning it might fix the issue. I will try that first.

 

Okay, about two months after replacing the purge valve solenoid, I got another CEL. P0455 and P0456 are back, this time joined by P0134. The internet indicates that P0134 is connected to O2 Sensor 1. What should I check next? Are the 2007s known for bad fuel caps?

FYI, I am not sure whether the last CEL was properly solved, as the polar vortex ate my battery, resetting the ECU.

 

Which valve did you buy to replace it, Genuine Honda part or some knock off that was cheaper?

Clear the codes and see if they come back. P0134 is linked to the rear upper O2 sensor. Might be time for a new sensor.

 

Replacement valve was OEM; got it from acuraoemparts.com. Could the sensor and the fuel pressure error be related, or are they separate issues?

 

First of all, is 36531-RCA-A02 the correct part number for that O2 sensor? Yes, I have checked a few other threads, but I just want a double-check.

Second, does anyone have any idea what else could be causing P0455/P0456? My TL has ~161K miles on it. Should I try the hoses linked to the purge valve solenoid? I want to fix this right, but I am not going to spend the time and money to shotgun the problem.

 

Get an NTD O2 sensor from rockauto or Denso. NTD is factory and Denso is a great alternative. OEM O2's are repackaged denso or NTD. FYI NTD is part of NGK (spark plug company). That should fix P0134. I used the Denso and it works great!

P0456 means the car is detecting a small leak from your fuel tank in terms of vapor venting to the atmosphere and also that it can't push the vapors into the engine to burn them.